[EGD-5954] Add CoD verification for bluetooth conn

Implement selective profile connection based on Class of Device

[EGD-6204] Add version.json to the udate package

`versin.json` is required for update process. This commit puts it back
to update package

[EGD-4851] Add URC support in sleep mode

When URCs come from the network and GSM is in sleep mode,
we wake up the modem to properly handle the incoming data.

[EGD-6198] SpinBox input callback consume fix

Fixed SpinBox consuming all input callbacks actions.

[EGD-5919] Fix: Fix logs from Service: Cellular, Fota

Fix: Remove misleading error message(change to debug/info).
Do not trace as error multiple retry. Minimize (to zero)
error logs on cold and hot start of the phone.

[EGD-5229] Cellular modem, change receiving to DMA

Changes implementation for receiving data from
cellular modem from IRQ byte-by-byte to DMA transactions.
Drop in replacement, works with current CMUX (TS07.10)

[EGD-6021] Cellular flush receiving buffer before initialization

Upon hot start the first data we receive comes from
modem from previous boot. This data is meaningless and
potenitally harmful. This adds: ignoring it

[EGD-5101] Add flow control configuration for cellular

Fix flow control pin configuration in OS.
Turn on flow control for cellular modem.

[EGD-6197] Unify settings menu text labels

Unifying setting menu text labels when it comes
to capital and small letters.

[EGD-6196] Replace venv command in harness readme

Replaced to avoid usage of python2

[EGD-5490] Add BT pairing documentation

Documentation gives a high-level overview of the following procedures:
-scanning
-pairing
-unpairing

[EGD-5989] Update quickstart article

Updated quickstart article with security-related info.

[EGD-5989] Update quickstart.md

Fixed a bit of a security risk.

[EGD-5965] Add BT-Harness API documentation

Added documentation:
* BT endpoint API
* BT-Harness tests

[EGD-6008] Create Pure flashing guide

Added small changes after trying to
boot the image on my own.

[EGD-6092] Create Pure flashing guide

Fixed some lines in the docs

[EGD-6092] Create Pure flashing guide

Ported Pure flashing guide on macOS/Win
to GitHub.

Co-authored-by: Michał Kamoń
<70628259+mkamonMdt@users.noreply.github.com>

[EGD-6092] Create Pure flashing guide

Ported Pure flashing guide macOS/Win to GitHub.

[EGD-5658] Add eInk CPU frequency hold

While the screen is being redrawn,
we block CPU frequency decreasing

[EGD-6150] Clean bottom bar after unpairing last device from the list

FORGET and CONNECT/DISCONNECT buttons were not removed after
the last device was removed from the list in All Devices window.