(#234) Fixes NuGet v3 Localhost Cache Issue

[JPRuskin]

Description Of Changes

This commit adds:

• A function to remove existing v3 cache folder(s)
• A call to that function after the Nexus setup script has pushed all of the packages

Motivation and Context

Nexus Repository stores the first FQDN it hears about for all future requests. As we initially upload packages via localhost, this is less than excellent and breaks future FQDN-based requests.

Testing

• [please hold]

Operating Systems Testing

• Windows 2019

Change Types Made

• [x] Bug fix (non-breaking change).
• [ ] Documentation changes.
• [x] PowerShell code changes.

Change Checklist

• [ ] Tests to cover my changes, have been added.
• [ ] All new and existing tests passed?

Related Issue

Fixes #234