Add editorconfig support in Razor

[allisonchou]

Tracking issue on the Razor side for adding editorconfig support in Razor.
Will likely need to discuss with Platform since the bulk of the work may need to be done on their side.

See 1) in: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1388770/ for original VSTS issue.

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There are a few different aspects to .editorconfig support, with different statuses and priorities:

Current status:

1. Support for indent_size, indent_style etc. generic formatting properties, as per the original linked issue above
   • Blocked by the Visual Studio editor, tracked internally by https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1408493
2. Support for start C# editor config controls in document formatting, eg code style
   • Not supported, is possible with bigger architectural changes like Umbrella: Replace IDynamicDocumentInfoProviders #6919
3. Support for razor specific editorconfig controls for formatting and other behaviours
   • Tracked by Desired Razor Formatting changes #8413

[allisonchou]

Tracking issues:
https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1408466
https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1408465 https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1408493

[allisonchou]

Other user asks:
https://developercommunity.visualstudio.com/t/editorconfig-settings-for-razor-files-/1675953
https://developercommunity.visualstudio.com/t/editorconfig-not-applying-to-cshtml/10044204

[y2kbugger]

It's not even just editorconfig, but also just normal C# naming style settings

[seangwright]

Is this related to "Code Cleanup on Save" (https://devblogs.microsoft.com/visualstudio/bringing-code-cleanup-on-save-to-visual-studio-2022-17-1-preview-2/) not working for Razor files?

VS's "Format Document" command formats a Razor file, but saving a Razor file does nothing even with "Code Cleanup on Save" enabled.

(I'm using VS 17.2.0)

[AllenD-MSFT]

This also related to https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1408493 (possibly a duplicate issue).