xFailOverCluster: Opt-in for module files common tests

[johlju]

Pull Request (PR) description

• Changes to xFailOverCluster
  • Opt-in for module files common tests (issue xFailOverCluster: Opt-in for module files common tests #119).
    • Removed Byte Order Mark (BOM) from the files; CommonResourceHelper.psm1 and FailoverClusters.stubs.psm1.

This Pull Request (PR) fixes the following issues:
Fixes #119

Task list:

• Change details added to Unreleased section of CHANGELOG.md?
• Added/updated documentation, comment-based help and descriptions in .schema.mof files where appropriate?
• Examples appropriately updated?
• New/changed code adheres to Style Guidelines?
• Unit and (optional) Integration tests created/updated where possible?

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This change is 

[msftclas]

@johlju,
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[codecov-io]

Codecov Report

Merging #120 into dev will not change coverage.
The diff coverage is n/a.

@@        Coverage Diff         @@
##           dev   #120   +/-   ##
==================================
  Coverage   90%    90%           
==================================
  Files        7      7           
  Lines      379    379           
==================================
  Hits       343    343           
  Misses      36     36

[johlju]

Reviewed 4 of 4 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable

[johlju]

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Review status: all files reviewed at latest revision, all discussions resolved, all commit checks successful.

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Comments from Reviewable