Format on Save touches files without changes

[grochocki]

trafficstars

Describe the bug

I noticed some things

• this also happens in VS 2019 when you hit Ctrl+Shift+S to save the whole solution
• but only after activating the first XAML file (having a XAML file open already when loading the solution but not activating it isn't enough)
• saving will "modify" all unchanged, unopened XAML files
• saving will "unmodify" the active XAML file
• saving will not change an opened XAML file, no matter if currently "modified" or not according to the UI
• the byte content of the "modified" and "unmodified" files match
• their SHA256 hashes (using PowerShell's Get-FileHash) match
• using "git status" says "no modifications"

Expected behavior No file changes, and no git modified files.

Additional context Reported in #289 and fixed in XamlStyler.Console in #379