Resolve symlink target relative to the symlink instead of the working directory (#15235)

[MatejKafka]

PR Summary

Fixes #15235.

PR Context

As described in the linked issue, the current implementation of symlink creation in the filesystem provider resolves relative symlink target paths relative to the working directory, instead of the location of the symlink. This PR fixes the issue by always resolving the path relative to the symlink. Additionally, since Path.Combine is used now, the path should be correctly resolved even if it does not start with ./ or .\, which is currently not the case.

It should be possible to add tests for this, but from a cursory look, there don't seem to by any tests of the filesystem provider touching the filesystem, so I did not add any.

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Total files changed: 1

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.cs : +1 -4

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[MatejKafka]

So, um, is there a chance of anyone looking at this PR? It's been almost 4 months now without any response.

[MatejKafka]

@SteveL-MSFT Apologies for pinging, but since @anmenaga, who is assigned, did not review the PR during the past 4 months, do you think you could review it instead?

[SteveL-MSFT]

@MatejKafka sorry, I'm reviewing this now

[SteveL-MSFT]

Please add tests here: https://github.com/PowerShell/PowerShell/blob/master/test/powershell/Modules/Microsoft.PowerShell.Management/FileSystem.Tests.ps1

[MatejKafka]

@SteveL-MSFT Done.

[microsoft-github-policy-service]

This pull request has been automatically marked as Review Needed because it has been there has not been any activity for 7 days.
Maintainer, please provide feedback and/or mark it as Waiting on Author