vty: add attributes to VTY commands indicating when they apply
vty: add attributes to VTY commands indicating when they apply

Change-Id: Ie0182351bd8a10085563c403dfab04c4d1b4305c
Depends: libosmocore I0efc57f2cb54798ba207ae6fef9af4771d96bfa9
Related: SYS#4937, OS#1601

osmocom/libosmo-abis,osmocom/libosmo-abis,osmocom/libosmo-abis