mesh: shell: Add app-key-add command
mesh: shell: Add app-key-add command

X-Original-Commit: 411fd62e81de3a0930998e6dd20ac0f46b8e842a

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble