Add task Create_Changelog_Branch

[johlju]

Pull Request

Pull Request (PR) description

Added

• Added task Create_Release_Branch to push a branch containing the updated
  change log after release. Fixes #351

Task list

• The PR represents a single logical change. i.e. Cosmetic updates should go in different PRs.
• Added an entry under the Unreleased section of in the CHANGELOG.md as per format.
• Local clean build passes without issue or fail tests (build.ps1 -ResolveDependency).
• Documentation added/updated in README.md.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• Unit tests added/updated. See DSC Community Testing Guidelines.
• Integration tests added/updated (where possible). See DSC Community Testing Guidelines.
• New/changed code adheres to DSC Community Style Guidelines.

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This change is 

[codecov]

Codecov Report

Merging #381 (c47c126) into main (6e032d1) will increase coverage by 1%.
The diff coverage is 73%.

@@         Coverage Diff         @@
##           main   #381   +/-   ##
===================================
+ Coverage    28%    30%   +1%     
===================================
  Files        42     43    +1     
  Lines      2261   2334   +73     
===================================
+ Hits        649    703   +54     
- Misses     1612   1631   +19     

Impacted Files	Coverage Δ
.build/tasks/Create_Release_Git_Tag.build.ps1	66% <66%> (ø)
.build/tasks/Create_Changelog_Branch.build.ps1	73% <73%> (ø)

[gaelcolas]

Looks good.