Adjust Indentation in XAML Rules and Common props/targets/tasks

[Nirmal4G]

Part of #4779

Context

Make Common props, targets and tasks easier to read and understand.
Make Visual Studio's Property Page (XAML) Rules easier to read and understand.

Part of the larger refactoring that'll lead into #1686

Changes Made

• Remove all trailing spaces
• Fixup new lines where necessary
  • Add new lines between every block to make it clear.
  • Remove unnecessary new lines to reduce scrolling.
• Adjust Indentation as per EditorConfig (2-space)

Notes

I'll also make sure not to mess up the git blame too much.
To make reviewing easier, I had split up the changes logically rather than a file.

The commits by themselves are logical changes. So, if possible, rebase merge them to preserve file history view in Git.

Also, please do note that these changes won't make much difference alone but with other formatting and refactors that follow this will make a world of difference in reading these files.

[Nirmal4G]

As you can see, some source files have also been touched. They belong to a different set of patches but I have extracted whitespace changes early on.

[Nirmal4G]

The PR #7165 removes the logic related to compatibility with MSBuild v4 and Dev11/Dev12. If that is approved, much of the changes here wouldn't apply. So, please wait until there's a verdict on that PR! And I'll rebase the PR accordingly.

[Forgind]

Looks good!

[Nirmal4G]

All done. Updated in response to #7165!

[Nirmal4G]

Updated in response to #7169!

[benvillalobos]

@Nirmal4G were these changes made via VS or some tool? The diff is massive, but if I can review each commit knowing it was done by automation it'd be easier to glance through instead of parsing every change.

Side note: this should merge as 1 commit

[Nirmal4G]

@benvillalobos Only 2nd commit (not all lines) were done by me, manually.

this should merge as 1 commit

You'll lose the clean diff, if not rebased. Anyway, it's just my suggestion.

About my PR tree format

I don't know what @microsoft's policy is but where I work, we have archive policy with OSS projects, where we take all the contributions up until major or minor releases and clean them up. After a few major versions, we take that archive's latest as base. And we'll do this over and over again.

Hence, having separated like this will make it easier for our archivists easier to clean up the commit tree. It'll also make it easier to blame and dig up historical commits easily and compare. Recently we also started using blame ignores to filter out the cosmetic commits.