bluez5: Added mSBC support in bluze5 backend native
This MR adds mSBC support onto the backend_native improvements by @fdanis from !355 (merged)
It should therefore be merged after !355 (merged) (as agreed here with @fdanis).
@pvir's remark regarding a potential problem when the headset supports mSBC but the audio gateway (=the computer/laptop) does not support the required "BT_VOICE_TRANSPARENT" transport mode is also resolved (see !391 (02f1f7a0))
I followed @pvirs suggestion to use the hci feature information to check if the adapter supports eSCO and Transparent Data.
Please let me know what you think, I'm pretty sure that can be improved