Uninstall modules using the required versions

[james-garriss]

💡 Summary

What is the work, as a high-level summary? There are two parts to this issue:

1. There is a script (UninstallModules.ps1) that uninstalls the modules that ScubaGear installs. This script hardcodes the set of modules to uninstall, and this list is out of sync with those that are installed. This script should be updated to use the modules listed in the required versions file (RequiredVersions.ps1).
2. This script only uninstalls modules, but that is not everything that ScubaGear installs. It should be improved so that it also uninstalls OPA and ScubaGear itself. Details can be found in the new and improved documentation.

Motivation and context

Why does this work belong in this project?

• Violating the DRY principle is a code smell.
• When the code is out of sync, it will fail to uninstall all of the modules, leaving unwanted debris on the user's computer.
• There should be one simple way for users to uninstall everything that ScubaGear installs.

Implementation notes

Please provide details for implementation:

• Remove hardcoding.
• Reference the required versions file.
• Uninstall those modules.
• Uninstall OPA.
• Uninstall ScubaGear
• Test, test, test.
• Test with both types of installation (install from PSGallery and download from GitHub).

Acceptance criteria

How do we know when this work is done?

• The uninstall modules script uninstalls everything!