Add PBP Test Suite

[mringwal]

This PR adds the PBP layer and WIDs for the PBP Test suite

It also fixes smaller details in other areas we've stumbled upon using one commit per fix.

PTS Project PBP code: https://github.com/bluekitchen/auto-pts/blob/develop-le-audio-tmap/autopts/ptsprojects/btstack/pbp.py