Allows enabling/disabling installed extensions

[jtreminio]

• Adds a "Disable" or "Enable" button to installed extensions.
• Adds a new hidden server setting persisting the choices.
• Disabled extensions are not loaded by the C# project, so their metadata (description, author, etc) must be read separately

I can keep the button in its current slot, or move it somewhere else.

All enabled:

Pending restart after disable:

One disabled:

[mcmonkey4eva]

I think you overcomplicated this -- you can already disable extensions by putting .disable on the end of the ext folder, I believe the main thing needed is just the UI button to automatically do that.

EDIT: on discord fair counter to this was given