(#204) Implement NuGet V3 Sources

[ryanrichter94]

Description Of Changes

• Add ChocolateyInternal as a V3 repo on the server.
• Edit scripts so Register-C4bEndpoint sets up clients using NuGet V3 source.
• Edit Jenkins jobs to use V3 sources.
• Edit README to reflect us using V3 repos with Nexus now.

Motivation and Context

NuGet V3 feeds are faster to query than V2 feeds.

Testing

1. Local VM testing

Operating Systems Testing

1. Windows Server 2022

Change Types Made

• ~[ ] Bug fix (non-breaking change).~
• ~[ ] Feature / Enhancement (non-breaking change).~
• [X] Breaking change (fix or feature that could cause existing functionality to change).
• ~[ ] Documentation changes.~
• [X] PowerShell code changes.

Change Checklist

• [X] Requires a change to the documentation.
• [X] Documentation has been updated.
• ~[ ] Tests to cover my changes, have been added.~
• [X] All new and existing tests passed?
• [X] PowerShell code changes: PowerShell v2 compatibility checked?

Related Issue

Fixes #204

[JPRuskin]

Added a few extra things and rebased it, retargeted develop - left them in a separate commit, but it should be squashed when we merge if you're happy with the additions.

[steviecoaster]

@JPRuskin Go ahead and clean up these commits and I'll get it merged.