[MOS-266] Call StateMachine implementation

With some tests, documentation and so on

[MOS-263] Fix DTMF handling in Pure

By accident, I've broke DTMF handling via Pure's keyboard
This was because of non strict description of API method.
Now, it has been unified to use ASCII code

[MOS-263] Remove unnecessary log

Removed log, which was left by accident

[MOS-263] Add HFP DTMF handling

Added handling of HFP DTMF code sending,
fixed DTMF sending in cellular's code

[MOS-366] Connect cellular events to HFP

Connected all (?) necessary cellular events to the HFP profile
Fixed audio issues when connected with HFP
Some cleanup

[MOS-420] Fix Call ending with sms reworked

Reworked ending with sms is now reworked. Sms is send by call app,
application messages is only providing template text.
Also call hangup and sms send order is changed due to delays caused by
sending sms.

[MOS-138] Correction of URC poll mode parameters

In poll mode, the CSQ will be requested every 15 minutes
and another attempt to switch the mode will be after 1 hour.
If the keyboard is unlocked or the USB cable is connected
or the BT car kit is connected, the URCs will be operated
in the reporting mode.

[MOS-228] GSM sleep mode dependend on communication with modem

After finishing communication with cellular,
we switch to sleep mode faster, saving the battery
at the same time.

[MOS-326] Change call logic removed from call window

Call logic is now removed from call window and call app.
There was spaghetti logic mixed in window and app, now
call logic is based on notificatins from service cellular.

[MOS-327] Removed call manager call logic in library

Moved call handling to separate library and removed CallManager
Apply suggestions from code review:
Co-authored-by: Bartosz Cichocki <sp2fet@gmail.com>
Co-authored-by: Mateusz Piesta <mateusz.piesta@mudita.com>

[MOS-264] Add handling of signal strength and operator name in HFP

To be able to display signal strength, operator name and
rest of status indicators in Bluetooth's HFP profile, some
refactor has been done.

[MOS-376] Add Call state notifications

Call state notifications are now send on state change.

[MOS-337] Fix no audio for incoming calls/messages

After the outgoing call was terminated,
the audio was terminated incorrectly,
therefore the next call did not ring.

[MOS-325] AudioServiceAPI removed from Call app

AudioServiceAPI is now removed from Call app.
Call audio routing is handled in service cellular.

[MOS-276] Fix exiting from template

Fix exiting from tempalate window
during call

[MOS-300] Remove unused variables

Remove unused variables from PVS Studio analysis

[MOS-269] Fix lock audio subsystem during voice call

Audio service is deadlocked on sentinel because IsBussy() method returns
that it's all the time bussy. Even though there is no ongoing audio
requested from either GSM or apps.

[MOS-296] Merge new master commits into merge-stable-wip

Merge new master commits

[MOS-296] Merge remote-tracking branch 'origin/stable'

Merge stable Harmony branch into merge wip branch

[MOS-226] Moved algorithms and their data to separate classes

This way we have controll over what does what, and can test
them separatelly
Logging statistics update more and better data presented