[EGD-6166] HSP ringing

Added HSP ring sound on incoming call event while
there's bluetooth connection active and HSP is
selected as the current profile.
Possibility of pick up/decline the call using
BT device buttons added.
Slightly changed HSP initialization according
to the UML-s added.
Changed call hangup handler in service cellular.

[EGD-6401] Fix bluetooth initialization

Fixed multiple initialization in A2DP and HSP profiles.

[EGD-6350] Added bluetooth device volume control

Bluetooth device volume control can be set by Pure Phone
while paired and is in A2DP mode. Temporarly disabled
HSP since it's not fully working and causing control issues.

[EGD-5260] Add A2DP playback to audio

Add basic playback capability using Bluetooth A2DP profile.
Only stereo/44100/16bit files are supported at the moment

Signed-off-by: Marcin Smoczyński <smoczynski.marcin@gmail.com>

[EGD-5945] Bluetooth-harness API messages

This PR:
* provides Bluetooth-Harness API messages definition [EGD-5944]
* provides Bluetooth-Harness API messages implementation
* provides Bluetooth-Harness API usage on harness side [EGD-5946]
* provides Bluetooth-Harness tests [EGD-5947]

[EGD-5954] Add CoD verification for bluetooth conn

Implement selective profile connection based on Class of Device

[EGD-6100] Add BT device turn off handling

After BT device disconnects (e.g. because of shutdown) Pure is now
aware of this

[EGD-6073] Fix text formatting in retry windows

Error message in retry windows was displayed incorrectly.

[EGD-6024] Return to All Devices window after attempt to retry action

Execution of retry pairing/unpairing/connecting took too long
to wait for it on retry popup. Fixed minor bugs.

[EGD-5984] Add BT implementation of added GUI actions

Implemented BT-side actions for GUI usage, e.g. connection status

[EGD-5940] Add BT device unpairing

Implemented possibility to forget/unpair a device via GUI

[EGD-5981] Fix BT scan stop issue

Btstack's scan stop call was not working properly thus force stop
function has been added

[EGD-5977] Fix empty BT devices list after pairing

After changing flow of settings windows, the stopScan command
is being executed right after executing pairing, so cleaning the
scan devices list is being done on scan start

[EGD-5764] Implement handling multiple BT profiles

To be able to connect to the BT device with more than one audio
profile, we need something to manage those profiles. Created here
ProfileManager made it convenient
To be able to work properly with BT, CPU freq has to be at least
at Level_5 - to be fixed!

[EGD-2634] Add pairing process result confirmation

Enable pairing BT devices in settings.
Connect popup and add adjust messages for pairing error handling.

[EGD-5856] Update Btstack

Updated to the latest version, fixes few bugs

Merge branch 'EGD-5737-merge-master-to-exp-lbr-fix'

[EGD-5737] Merge master into experimental

Synchronize with master before merging

[EGD-5700] Fix Bluetooth pairing

To be able to proper propagate the pair message there was a need
for Command wrapper (to be able to send command and parameter in
one piece)

[EGD-4340] Refactor bluetooth settings and add device windows

Rewrote these windows in a proper way.
Fixed few minor issues.
GUI adjustments.