Fix redundant CR in formatted text copy (#4190)

## Summary of the Pull Request

When `GenHTML` or `GenRTF` encountered an empty line, they assumed that `CR` is the last character of the row and wrote it, even though in general `CR` and `LF` just break the line and instead of them either `<BR>` in HTML or `\line` in RTF is written. Don't know how I missed that in #2038.

Another question is whether the `TextAndColor` structure which these methods receive and which is generated by `TextBuffer::GetTextForClipboard` should really contain `\r\n` at the end of each row. I think it'd be cleaner if it didn't esp. that afaik these last 2 characters don't have associated valid color information.

## References

<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist
* [X] Closes #4187
* [X] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA
* [ ] Tests added/passed - there aren't any related tests, right?
* [ ] Requires documentation to be updated
* [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #4147

<!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed
Copied various terminal states and verified the generated HTML.

(cherry picked from commit 1ca2912)

src/buffer/out/textBuffer.cpp

@@ -1243,26 +1243,6 @@ std::string TextBuffer::GenHTML(const TextAndColor& rows, const int fontHeightPo
 
             for (size_t col = 0; col < rows.text.at(row).length(); col++)
             {
-                // do not include \r nor \n as they don't have attributes
-                // and are not HTML friendly. For line break use '<BR>' instead.
-                const bool isLastCharInRow =
-                    col == rows.text.at(row).length() - 1 ||
-                    rows.text.at(row).at(col + 1) == '\r' ||
-                    rows.text.at(row).at(col + 1) == '\n';
-
-                bool colorChanged = false;
-                if (!fgColor.has_value() || rows.FgAttr.at(row).at(col) != fgColor.value())
-                {
-                    fgColor = rows.FgAttr.at(row).at(col);
-                    colorChanged = true;
-                }
-
-                if (!bkColor.has_value() || rows.BkAttr.at(row).at(col) != bkColor.value())
-                {
-                    bkColor = rows.BkAttr.at(row).at(col);
-                    colorChanged = true;
-                }
-
                 const auto writeAccumulatedChars = [&](bool includeCurrent) {
                     if (col >= startOffset)
                     {
@@ -1289,6 +1269,27 @@ std::string TextBuffer::GenHTML(const TextAndColor& rows, const int fontHeightPo
                     }
                 };
 
+                if (rows.text.at(row).at(col) == '\r' || rows.text.at(row).at(col) == '\n')
+                {
+                    // do not include \r nor \n as they don't have color attributes
+                    // and are not HTML friendly. For line break use '<BR>' instead.
+                    writeAccumulatedChars(false);
+                    break;
+                }
+
+                bool colorChanged = false;
+                if (!fgColor.has_value() || rows.FgAttr.at(row).at(col) != fgColor.value())
+                {
+                    fgColor = rows.FgAttr.at(row).at(col);
+                    colorChanged = true;
+                }
+
+                if (!bkColor.has_value() || rows.BkAttr.at(row).at(col) != bkColor.value())
+                {
+                    bkColor = rows.BkAttr.at(row).at(col);
+                    colorChanged = true;
+                }
+
                 if (colorChanged)
                 {
                     writeAccumulatedChars(false);
@@ -1310,10 +1311,10 @@ std::string TextBuffer::GenHTML(const TextAndColor& rows, const int fontHeightPo
 
                 hasWrittenAnyText = true;
 
-                if (isLastCharInRow)
+                // if this is the last character in the row, flush the whole row
+                if (col == rows.text.at(row).length() - 1)
                 {
                     writeAccumulatedChars(true);
-                    break;
                 }
             }
         }
@@ -1430,24 +1431,6 @@ std::string TextBuffer::GenRTF(const TextAndColor& rows, const int fontHeightPoi
 
             for (size_t col = 0; col < rows.text.at(row).length(); ++col)
             {
-                const bool isLastCharInRow =
-                    col == rows.text.at(row).length() - 1 ||
-                    rows.text.at(row).at(col + 1) == '\r' ||
-                    rows.text.at(row).at(col + 1) == '\n';
-
-                bool colorChanged = false;
-                if (!fgColor.has_value() || rows.FgAttr.at(row).at(col) != fgColor.value())
-                {
-                    fgColor = rows.FgAttr.at(row).at(col);
-                    colorChanged = true;
-                }
-
-                if (!bkColor.has_value() || rows.BkAttr.at(row).at(col) != bkColor.value())
-                {
-                    bkColor = rows.BkAttr.at(row).at(col);
-                    colorChanged = true;
-                }
-
                 const auto writeAccumulatedChars = [&](bool includeCurrent) {
                     if (col >= startOffset)
                     {
@@ -1470,6 +1453,27 @@ std::string TextBuffer::GenRTF(const TextAndColor& rows, const int fontHeightPoi
                     }
                 };
 
+                if (rows.text.at(row).at(col) == '\r' || rows.text.at(row).at(col) == '\n')
+                {
+                    // do not include \r nor \n as they don't have color attributes.
+                    // For line break use \line instead.
+                    writeAccumulatedChars(false);
+                    break;
+                }
+
+                bool colorChanged = false;
+                if (!fgColor.has_value() || rows.FgAttr.at(row).at(col) != fgColor.value())
+                {
+                    fgColor = rows.FgAttr.at(row).at(col);
+                    colorChanged = true;
+                }
+
+                if (!bkColor.has_value() || rows.BkAttr.at(row).at(col) != bkColor.value())
+                {
+                    bkColor = rows.BkAttr.at(row).at(col);
+                    colorChanged = true;
+                }
+
                 if (colorChanged)
                 {
                     writeAccumulatedChars(false);
@@ -1513,10 +1517,10 @@ std::string TextBuffer::GenRTF(const TextAndColor& rows, const int fontHeightPoi
                                    << " ";
                 }
 
-                if (isLastCharInRow)
+                // if this is the last character in the row, flush the whole row
+                if (col == rows.text.at(row).length() - 1)
                 {
                     writeAccumulatedChars(true);
-                    break;
                 }
             }
         }