Core: Add support for Retail addon compartment

[PatTheMav]

This PR adds support for the addon compartment added in Dragonflight:

• The Retail TOC file adds the new values of the corresponding functions (alternatively this can be implemented entirely in code, ymmv.
• A new addon compartment module adds the corresponding functions to add an AzeriteUI item with a corresponding tooltip
• The menu item will open the AzeriteUI options on left-button mouse click and the movable frame manager on a right click

The compartment is also added to the minimap in Retail WoW in the same position as the MinimapButton addon. If MBB is installed, the addon compartment button is re-parented to the "Hider" frame to make space for its own implementation.

[Goldpaw]

By the time I got to this, it had conflicts with the current Minimap.lua. So I added your fix manually instead, since that was easier than me trying to figure out how to realign the fix. :)

Closing this since the code has been included now.