feat: 290 properties for width-height of image (#359)

Closes #290

### Summary of Changes

* feat: Properties for width and height of an image should be returned
in pixels.

---------

Co-authored-by: megalinter-bot <129584137+megalinter-bot@users.noreply.github.com>

src/safeds/data/image/containers/_image.py

@@ -82,6 +82,30 @@ def format(self) -> ImageFormat:
         """
         return self._format
 
+    @property
+    def width(self) -> int:
+        """
+        Get the width of the image in pixels.
+
+        Returns
+        -------
+        width : int
+            The width of the image.
+        """
+        return self._image.width
+
+    @property
+    def height(self) -> int:
+        """
+        Get the height of the image in pixels.
+
+        Returns
+        -------
+        height : int
+            The height of the image.
+        """
+        return self._image.height
+
     # ------------------------------------------------------------------------------------------------------------------
     # Conversion
     # ------------------------------------------------------------------------------------------------------------------

tests/safeds/data/image/containers/test_image.py

@@ -54,6 +54,28 @@ def test_should_return_correct_format(self, image: Image, format_: ImageFormat)
         assert image.format == format_
 
 
+class TestProperties:
+    @pytest.mark.parametrize(
+        ("image", "width", "height"),
+        [
+            (
+                Image.from_jpeg_file(resolve_resource_path("image/white_square.jpg")),
+                1,
+                1,
+            ),
+            (
+                Image.from_png_file(resolve_resource_path("image/snapshot_boxplot.png")),
+                640,
+                480,
+            ),
+        ],
+        ids=["[1,1].jpg", "[640,480].png"],
+    )
+    def test_should_return_image_properties(self, image: Image, width: int, height: int) -> None:
+        assert image.width == width
+        assert image.height == height
+
+
 class TestToJpegFile:
     @pytest.mark.parametrize(
         "path",