Feature - Way to rest all party pokemon at Pokecenter / long rest

[magroader]

There is currently a ZZZ button to fully rest a single Pokemon, but there is no way to full heal ALL of your party Pokemon (via a long rest or Pokemon center). This could be placed in the "Group" screen suggested in #422.

This would also allow removing the ZZZ button from individual Pokemon, because (AFAIK) there is no particular way to full heal a single Pokemon.