[Feature]: Add admin setting for regional sharing radio presets

[MeshMapperBot]

Platform: Other

Description:
add admin setting to set regions radio preset for sharing in misc areas.

Discord: https://discord.com/channels/1463383723327356992/1466576054670987294/1512583555757375619

Submitted by: littleaton (Discord)

[Littleaton]

unless this can be pulled via radio settings when someone uses the app something to populate it on the backend. ..