Sunset setting KeepNewlineAfter

[nojaf]

Description

The setting KeepNewlineAfter is in some shape or form the successor of PreserveEndOfLine although in a limited set of cases.

This setting would register a newline after = in the original source code (via Trivia parsing) and preserve that newline.

For example:

let a = 
    42

With KeepNewlineAfter the code remains unchanged after formatting.

Problem statement

This main issue with this setting is that it shouldn't preserve stylistic choice from the source code as these are purely driven by the user. It is the user responsibility to write consistent code and that beats the purpose of a code formatter.

Alternative

As #721 is progressing it allows for more freedom in configuring the output of the formatted code.
The user can limit the length of certain code constructs via settings.
These setting will enforce a consistent codebase and partially remove the need for having KeepNewlineAfter setting.

In the example above, the MaxLetBindingWidth setting could be set to 0 and lead to the same result.

//cc @jindraivanek

[nojaf]

The setting was removed in #721