Removes PSGallery availability checks

[OCram85]

📦 Changes

• removes Get-PSGalleryApiAvailability references and the function itself
• removes Check-PSGalleryApiAvailability references and the function itself
• removes unused variables
• Removes Pester test cases for
  • Get-PSGalleryApiAvailability
  • Check-PSGalleryApiAvailability

📔 General Changes

• Introduced vscode workspace settings to enable common style
  • VSCode settings contains defaults for the editor and PowerShell extension.
  • Tried to adopt PowerShellPracticeAndStyle

🔖 Ref

• fixes Check-PSGalleryApiAvailability prevents working with PSGallery #369

[msftclas]

All CLA requirements met.

[edyoung]

Mi Marco, thanks for the PR. I don't see a problem, and expect to merge it once we have fixed the CI tests, which are currently failing for an unrelated reason. For future reference, in general I find it easier to review if a functional change is not 'mixed in' with reformatting the affected files, because it's trickier to spot the actual changes among all the style updates.

[alerickson]

@OCram85 there's a missing } that should be on line 204 of PSGetModuleSource.Tests.ps1 (closing out the describe block on line 87), but everything else looks good

[OCram85]

@alerickson: Thanks for the help :D - I've just updated the PR.

@edyoung: I'm not sure if I messed with the common style in this project. I personally like adding defaults with vscode workspace settings. If needed - I would also split this PR and introduce the defaults with a separate PR which also would include fixing the style issues in all files ^^