DnsServerEDns: New resource proposal

[johlju]

Pull Request (PR) description

• xDnsServer
  • Added new resource
  • DnsServerEDns - resource to enforce extension mechanisms for DNS (EDNS) settings (issue #194).
  • Added new private function Assert-TimeSpan to help assert that a value provided in a resource can be converted to a [System.TimeSpan] and optionally evaluates so it is not below a minium value or over a maximum value.

This Pull Request (PR) fixes the following issues

• Fixes #194

Task list

• [x] 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).
• [x] Resource documentation added/updated in README.md.
• [x] Resource parameter descriptions added/updated in README.md, schema.mof and comment-based help.
• [x] Comment-based help added/updated.
• [x] Localization strings added/updated in all localization files as appropriate.
• [x] Examples appropriately added/updated.
• [x] Unit tests added/updated. See DSC Community Testing Guidelines.
• [x] Integration tests added/updated (where possible). See DSC Community Testing Guidelines.
• [x] New/changed code adheres to DSC Community Style Guidelines.

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This change is 

[codecov[bot]]

Codecov Report

Merging #224 (7bb4d52) into main (49cd773) will increase coverage by 0%. The diff coverage is n/a.

@@         Coverage Diff         @@
##           main   #224   +/-   ##
===================================
  Coverage    85%    86%           
===================================
  Files        16     16           
  Lines      1550   1582   +32     
===================================
+ Hits       1331   1363   +32     
  Misses      219    219           

Impacted Files	Coverage Δ
source/xDnsServer.psm1	99% <0%> (+<1%)	:arrow_up:

[johlju]

@Sudman1 if you have some time then please review this. It is a big PR.

[johlju]

@Sudman1 thank you!