Unicode Map Accessible in Keymap GUI

If a keyboard uses UNICODEMAP_ENABLE, there could be a tab (named "Unicode") giving easy access to these keys and properly displaying their unicode output. Other keys relevant to QMK's unicode feature (e.g. UC_MOD) could also be accessible here. Also some way to access or emulate the QMK XP() function to optionally set up overrides of these keys with shift would be very convenient.

At present it is already possible to map keys that are set up in an unicode map, they just are represented by a hex code that the user might not even know if it isn't mapped by default.