xSQLServerSetup: Fixes failover cluster bugs with shared disks

[johlju]

Changes to xSQLServerSetup

• Now it can correctly determine the right cluster when only parameter InstallSQLDataDir is assigned a path (issue xSQLServerSetup: Fails to determine needed cluster disk if only InstallSQLDataDir is assigned a path #401).
• Now the only mandatory path parameter is InstallSQLDataDir when installing Database Engine (issue xSQLServerSetup: During cluster install optional arguments for setup.exe are required by the resource #400).
• It now can handle mandatory parameters, and are not using wildcards to find the variables containing paths (issue xSQLServerSetup: When mapping cluster disks, use $PSBoundParameters not Get-Variable #394).

This Pull Request (PR) fixes the following issues:
Fixes #394
Fixes #400
Fixes #401

• 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 #404 into dev will increase coverage by <1%.
The diff coverage is 100%.

@@         Coverage Diff          @@
##            dev   #404    +/-   ##
====================================
+ Coverage    68%    68%   +<1%     
====================================
  Files        31     31            
  Lines      3171   3183    +12     
====================================
+ Hits       2180   2192    +12     
  Misses      991    991

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[johlju]

Reviewed 1 of 4 files at r1, 4 of 4 files at r2.
Review status: all files reviewed at latest revision, 2 unresolved discussions.

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README.md, line 857 at r2 (raw file):

* Target machine must be running Windows Server 2008 R2 or later.
* For configurations that utilize the 'InstallFailoverCluster' action, the following parameters are required (beyond those required for the standalone installation)

Add full stop (.) to each sentence.

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README.md, line 860 at r2 (raw file):

  * InstanceName (can be MSSQLSERVER if you want to install a default clustered instance)
  * FailoverClusterNetworkName
  * When installation SQL Server database engine:

Grammar wrong. 'Parameters mandatory when...'
Remove ':'

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Comments from Reviewable

[johlju]

Looks good to me. Waiting until tomorrow to merge if someone else wants to comment on anything.

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Reviewed 1 of 1 files at r3.
Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable

[johlju]

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Review status: all files reviewed at latest revision, all discussions resolved, all commit checks successful.

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Comments from Reviewable