Draft UI, Minimap, and Contextual Menu

Over the last few days, many things have been happening - unfortunately one of those things was not: work on the game :(.

As mentioned on twitter, course has started (lots of travel into the city), had wisdom tooth and molar extracted, lots and lots of distractions XD.

So heres what I've managed to get done (now that I'm lucid again):

• Added a minimap, using culling masks on a second camera + a viewport texture.
• Added a relocation line (inspired by DK1), shows the direction of the core on the minimap when not in sight.
• Added Context Menu - a menu which changes its contents based on the current selection/mode.
  • In place currently is (placeholding): Excavation Mode, Build Mode, and Investigation Mode.
• Added resource counts above minimap, keeping them within the UI for ease of readability.
• Added a central UI bar, which will contain a breakdown of selected units/buildings once finished.

All of the above is visible in the attached video :).

Thanks for checking in!