[Build, CI, Localization, Enterprise] Leverage Microsoft's own admxgen to auto-generate the ADMX & ADML files from JSON & CSV

[no-identd]

Description of the new feature / enhancement:

• What it says in the title.

Scenario when this would be used:

• Less tedious work for @htcfreek & all y'all PowerToys contributors
• Quasi-prerequisite to subsequently make it SLIGHTLY easier to deal with the numerous permutations/combinations of feature enablement/disablement

Supporting information:

• https://github.com/FSLogix/admxgen (which IS owned by Microsoft, for those not familiar, Microsoft bought FSLogix a couple of years ago, similar to how Microsoft eventually bought DesktopStandard Corporation for their PolicyMaker product, to yield the group policy system we nowadays know.)

See also, IFF you're the kind of sysadmin who groks why I add this seemingly superfluous see also block here:

• The infamous reg2gpo powershell script, easily found on Google (careful it has VERY minor bugs)
• https://github.com/vcctr/reg2gpp (which ain't the same as the above)
• [MS-GPREG]
• Group Policy ADMX Syntax Reference Guide.doc
• Derek Melber's Windows Group Policy Windows Server 2008 and Windows Vista Resource Kit
• https://github.com/exchange12rocks/PSGPPreferences