xSQLServerAlwaysOnAvailabilityGroupReplica: Added EndpointPort and EndpointUrl as read-only properties to the schema

[randomnote1]

Pull Request (PR) description
Added EndpointPort and EndpointUrl as read-only properties to the schema.

This Pull Request (PR) fixes the following issues:
Fixes: #477

Task list:

• Change details added to Unreleased section of CHANGELOG.md?
• Added/updated documentation, comment-based help and descriptions in .schema.mof files where appropriate?
• Examples appropriately updated?
• New/changed code adheres to Style Guidelines?
• Unit and (optional) Integration tests created/updated where possible?

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This change is 

[codecov-io]

Codecov Report

Merging #803 into dev will not change coverage.
The diff coverage is n/a.

@@         Coverage Diff         @@
##            dev   #803   +/-   ##
===================================
  Coverage    96%    96%           
===================================
  Files        30     30           
  Lines      3256   3256           
===================================
  Hits       3139   3139           
  Misses      117    117

[johlju]

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Reviewed 3 of 3 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved.

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