Invoke-Git: Fix new line in returned strings

[johlju]

Pull Request

Pull Request (PR) description

• Invoke-Git
  • No longer write a new line to the end of string for the returned properties
    StandardOutput and StandardError.

This Pull Request (PR) fixes the following issues

Possibly #84

Task list

• Added an entry to the change log under the Unreleased section of the
  file CHANGELOG.md. Entry should say what was changed and how that
  affects users (if applicable), and reference the issue being resolved
  (if applicable).
• Documentation added/updated in README.md.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• Examples appropriately added/updated.
• Unit tests added/updated.
• Integration tests added/updated (where possible).
• New/changed code adheres to DSC Community Style Guidelines.

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This change is 

[codecov]

Codecov Report

Merging #94 (d8de6b2) into main (df9cf25) will increase coverage by 0%.
The diff coverage is 100%.

@@        Coverage Diff         @@
##           main   #94   +/-   ##
==================================
  Coverage    97%   97%           
==================================
  Files        38    38           
  Lines       893   895    +2     
==================================
+ Hits        875   877    +2     
  Misses       18    18           

[johlju]

Reviewed 2 of 2 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @johlju)