Break Registry functions out into new Repo

[VertigoRay]

The are two registry functions that should be managed and tested independently, but potentially together:

• Remove-OneDriveRegKey (See first comment, below)
• Remove-OneDriveExcessRegKeyValues

I'm thinking a new module called: RegistryPlus. Alternatively, we could look into adding a PR to actual MSFT Registry Resource...

Be sure to ...

• Update REQUIREMENTS.psd1.

[VertigoRay]

Apparently this should remove a Key:

Registry Test
{
    Ensure = 'Absent'
    Key = 'HKLM:\Software\Test'
    ValueName = ''
}

... yes, it's documented!