Exclude duplicate files for Run.Path and CodeCoverage.Path

[fflaten]

PR Summary

Updates Find-File and Get-CodeCoverageFilePaths internal functions to exclude duplicate files when provided overlapping Path values to search in. This affects:

• Test file paths provided using -Path / Run.Path
• Code Coverage source file paths provided using -CodeCoverage / CodeCoverage.Path
• Containers created using New-PesterContainer -Path ..
  • Mulitple containers can still call the same file, e.g. to invoke it with different Data (parameters)

PR also:

• Refactors Get-CodeCoverageFilePaths to use Get-ChildItem -File -Recurse for increased performance.
• Refactors New-PesterContainer to avoid multiple filesystem searches when provided array of Data for increased performance.

Fix #2530

PR Checklist

• [x] PR has meaningful title
• [x] Summary describes changes
• [x] PR is ready to be merged
  • If not, use the arrow next to Create Pull Request to mark it as a draft. PR can be marked Ready for review when it's ready.
• [x] Tests are added/update (if required)
• [ ] Documentation is updated/added (if required)

[fflaten]

@nohwnd CI disabled in AzDO?

[fflaten]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[nohwnd]

/backport to rel/5.6.x

[github-actions[bot]]

Started backporting to rel/5.6.x: https://github.com/pester/Pester/actions/runs/9879992903