Unify ra and cnc main menu logic and clean up the main menus.
Move a bunch of buttons into an Extras submenu and the server browser.
Move CncMenuPaletteEffect to ra so it can be used elsewhere and rename it to MenuPaletteEffect.
Update CHANGELOG: add entries for new menus and reword some existing entries
Merge pull request #4520 from ScottNZ/new-menu

Unify ra and cnc main menu logic