Bluetooth: shell: Reorder commands in logical order of use

Reordered the commands in btshell to represent the logical
order of use. Moved advertise and scan before connect
command.

Change-id: Id64509e39848109a6df7ddb1306b6bd221b65c40
Signed-off-by: Vinayak Chettimada <vinayak.kariappa.chettimada@nordicsemi.no>