Kiota: Replace PowerShell script with inline MSBuild task for improved performance

[bkoelman]

Also updates kiota version and refreshes docs.

QUALITY CHECKLIST

• Changes implemented in code
• Complies with our contributing guidelines
• N/A: Adapted tests
• Documentation updated

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.35%. Comparing base (749e588) to head (4263c77).
Report is 1 commits behind head on openapi.

Additional details and impacted files

@@           Coverage Diff            @@
##           openapi    #1696   +/-   ##
========================================
  Coverage    90.35%   90.35%           
========================================
  Files          462      462           
  Lines        14076    14076           
  Branches      2198     2198           
========================================
  Hits         12719    12719           
  Misses         918      918           
  Partials       439      439           

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