floss: Rename list-devices and support bonded devices

Rename list-devices to just list and support listing either bonded or
found devices. This will let users both look at their bonded device list
as well as devices found during the most recent discovery session.

Bug: 196887009
Tag: #floss
Test: In btclient, check "list found" and "list bonded"
Change-Id: I907c0dc46949c03723c3d0dab068ed1a8b2f7a83