Fix New-Item -ItemType Hardlink to resolve target to absolute path and not allow link to itself

[SteveL-MSFT]

PR Summary

The FileSystemProvider was simply passing the target to the Win32 API which uses the process working directory as the base of the relative directory and fails to find the target. Fix for that is to use PowerShell SessionState to resolve the target to an absolute path before calling the Win32 API.

When -Force is used, the FileSystemProvider basically does a delete and then create. However, in the case of a hardlink, this deletes the target so the Win32 API complains. The fix here is to check if the path and target is the same and not allow this to happen even if -Force is used. Did not change the existing symbolic link behavior which creates a link to itself since the Win32 API allows it.

PR Context

Fix #18623
Fix #18620

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[pull-request-quantifier-deprecated]

This PR has 22 quantified lines of changes. In general, a change size of upto 200 lines is ideal for the best PR experience!

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Label      : Extra Small
Size       : +21 -1
Percentile : 8.8%

Total files changed: 3

Change summary by file extension:
.cs : +6 -0
.resx : +4 -1
.ps1 : +11 -0

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