xADUser: Fix Password Property Being Updated Whenever Another Property is Changed

[X-Guardian]

Pull Request (PR) description

This PR fixes the issue that Password property is being updated whenever another property is changed even though it was already in the desired state.

This is achieved by adding a call to the Test-Password function from within the relevant code block of the Set-TargetResource function.

This Pull Request (PR) fixes the following issues

• Fixes xADUser: Password Property is Updated Whenever Another Property is Changed #384

Task list

• Added an entry under the Unreleased section in the CHANGELOG.md.
  Entry should say what was changed, and how that affects users (if applicable).
• Resource documentation added/updated in resource directory README.md.
• Resource parameter descriptions added/updated in schema.mof
  and comment-based help.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• Examples appropriately added/updated.
• Unit tests added/updated. See DSC Resource Testing Guidelines.
• Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

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This change is 

[codecov-io]

Codecov Report

Merging #389 into dev will increase coverage by <1%.
The diff coverage is 100%.

@@         Coverage Diff          @@
##            dev   #389    +/-   ##
====================================
+ Coverage    92%    92%   +<1%     
====================================
  Files        20     20            
  Lines      2530   2538     +8     
  Branches     10     10            
====================================
+ Hits       2335   2343     +8     
  Misses      185    185            
  Partials     10     10

[johlju]

Awesome work! 😃

Reviewed 1 of 2 files at r1, 1 of 1 files at r2, 1 of 1 files at r3, 1 of 1 files at r4.
Reviewable status: complete! all files reviewed, all discussions resolved