[CI] Introduce shared Windows toolchain setup action

[aobolensk]

• add .github/actions/setup-windows-toolchain composite action
• use this new action in all Windows jobs to configure MSVC and tooling

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.15%. Comparing base (d1764d8) to head (68d94d5).
Report is 3 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #470   +/-   ##
=======================================
  Coverage   92.15%   92.15%           
=======================================
  Files          11       11           
  Lines         357      357           
  Branches      116      127   +11     
=======================================
  Hits          329      329           
  Misses         10       10           
  Partials       18       18           

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