Porting Enable-PSRemoting and its Tests

[mirichmo]

Fixes #1193 for most scenarios. The remaining scenario to be addressed is the Nano Server bring-up scenario. To continue supporting that scenario, I left the Install-PowerShellRemoting script in place.

This change

1. Ports Enable-PSRemoting and Disable-PSRemoting to PowerShell Core
2. Adds side-by-side PowerShell Core remoting support to the PSSessionConfiguration cmdlets and PSRemoting cmdlets.
3. Ports PSSessionConfiguration tests

This change also introduces a behavioral difference. The PSRemoting and PSSessionConfiguration cmdlets are now context-sensitive and only work for endpoints that match the PowerShell type. For example, Get-PSSessionConfiguration, when run in PowerShell Core, will only return PowerShell Core WinRM endpoints. It will only modify PowerShell Core WinRM endpoints and cannot be used to configure Windows PowerShell endpoints.

[chunqingchen]

Can you please resolve the conflict?

[mirichmo]

At some point. I'm trying to find time to resolve the test failures.

[chunqingchen]

cool !

[PaulHigin]

@mirichmo I am not sure how I missed this being assigned to me as a reviewer. But I will review it today.

[mirichmo]

The tests aren't passing yet so it still needs some work. You are always welcome to take a look though

[PaulHigin]

@mirichmo I went through the code changes and made some minor changes in my fork. I also made some fixes in the test file. Overall I think this looks good and is the right way to implement WinRM based remoting enabling and endpoint management. Please see the patch file I sent you offline that has my minor changes.

[mirichmo]

@daxian-dbw This is ready for merge now.

[iSazonov]

This change also introduces a behavioral difference

It seems we need update docs - should we set the label?

[daxian-dbw]

@iSazonov good point. I added the label to both this PR and the issue.