Add Move-PSKoanLibrary Function

[vexx32]

PR Summary

Adds a Move-PSKoanLibrary public function which moves the entire PSKoans library folder and sets the new location in the module configuration.

Context

Resolves #325

Changes

• Added Move-PSKoanLibrary command
• Added tests for new command

Tangential:

• Fixed a couple minor issues with Set-PSKoanLocation that I found in the process.
• Added an automatic PSKoans. prefix for ErrorIds emitted from New-PSKoanErrorRecord

Checklist

• Pull Request has a meaningful title.
• Summarised changes.
• Pull Request is ready to merge & is not WIP.
• Added tests / only testable interactively.
  • Make sure you add a new test if old tests do not effectively test the code changed.
• Added documentation / opened issue to track adding documentation at a later date.

[steviecoaster]

LGTM!