MFC r342945, r342947, r343020

MFC r342945, r342947, r343020

Add `bluetooth-config` script to simplify setting up bluetooth connections to
devices like mice, keyboards, bt-audio, ...

This script currently allows scanning for nearby devices, adds one to
/etc/bluetooth/hosts, adds an entry to hcsecd's conf and if it is a HID, add an
entry to bthidd's configs, as well.

Submitted by:   erdgeist <erdgeist at erdgeist.org>
Approved by:    bapt
MFC after:      2 weeks
Differential Revision:  D3778
Reviewers:      bapt, emax