AdfsProperties: Remove Obsolete Properties

[X-Guardian]

Pull Request (PR) description

This PR removes the obsolete properties PromptLoginFederation and PromptLoginFallbackAuthenticationType from the AdfsProperties resource.

This Pull Request (PR) fixes the following issues

• Fixes #34

Task list

• [x] 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.
• [x] Unit tests added/updated. See DSC Resource Testing Guidelines.
• [ ] Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• [x] New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

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This change is 

[codecov[bot]]

Codecov Report

Merging #35 into dev will decrease coverage by <.01%. The diff coverage is n/a.

@@            Coverage Diff            @@
##              dev     #35      +/-   ##
=========================================
- Coverage   98.31%   98.3%   -0.01%     
=========================================
  Files          16      16              
  Lines        2131    2129       -2     
=========================================
- Hits         2095    2093       -2     
  Misses         36      36

Impacted Files	Coverage Δ
...urces/MSFT_AdfsProperties/MSFT_AdfsProperties.psm1	100% <ø> (ø)	:arrow_up:

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