The nuget installation leaves private installation commandlets available after installation

Steps to reproduce

The EPiServer.CMS.UI.Core nuget package exposes commandlets that aren't meant for public use.

These commandlets should be encapsulated and unloaded in the same way that's done in EPiServer.Packaging. Having them exposed indicates a public api, but they're really only intended for use by the our package installation.

Exposing them can also lead to conflicts with other commandlets with the same names, and then we can't know which is actually executing.

The available commandlets are reported by the Get-Module commandlet in package manager console in Visual Studio.

Steps to reproduce

1. Install EPiServer.CMS.UI.Core

2. Open Package Manager Console

3. Execute Get-Module

The following commandlets are available, but shouldn't be

Get-ProtectedModulesPath

Get-Web-Config

Remove-Assembly

Update-PackagesConfig

Remove-AddOnFolder

Update-AssemblyBinding

Get-ModulesRepositoryPath

Remove-RepositoryModule