List nearby regions

WORLDGUARD-3579 - Reported by leasoncre

add feature that will list nearby regions from current location. and how far away they are

/rg list near
-would return something like
1. Spawn 100
2. jackie12 130

returns a list of regions that have a block protected within that radius.
-optional: spherical radius. X/Z axis are only directions needed for towny, (we protect bedrock-to-sky)

setting up new towns for players can be tricky if you don't know where nearby towns are (ie a new town must be at least 200 blocks from an existing town)

PS. there may be a plugin that does this, but i can't find it.

Thank you.