Add fixer for ClassUsingAttributeInsteadOfInheritanceAnalyzer

[Sergio0694]

Closes #583

This PR adds a code fixer for ClassUsingAttributeInsteadOfInheritanceAnalyzer.

PR Checklist

• Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• Based off latest main branch of toolkit
• PR doesn't include merge commits (always rebase on top of our main, if needed)
• Tested code with current supported SDKs
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• Contains NO breaking changes
• Every new API (including internal ones) has full XML docs
• Code follows all style conventions

[Sergio0694]

Hey @Youssef1313, would you have any suggestions on how to handle whitespaces in the code fixer? 😅

[Youssef1313]

Hey @Youssef1313, would you have any suggestions on how to handle whitespaces in the code fixer? 😅

Trivia isn't trivial 😄

Given a quick look, I don't see why there is an extra new line. I'll see if I could debug it.

[Youssef1313]

@Sergio0694 The identifier name already has a trailing EndOfLineTrivia, so when you add a base type, the new line remains. You'll have to remove the trivia from the identifier name. But when other interfaces exist, the trailing trivia of identifier name will be a space that you want to keep.

Instead of having to handle all that manually, which is hard to get right (for example, you need to keep trailing trivia after identifier name even if there is no existing base list if the user uses K&R braces), you can use SyntaxGenerator to handle everything for you.

#590