[EGD-6637] Cleanup locks structure

Renaming existing locks namespace and created proper directory
structure.

[EGD-6315] Fix issues during saving new APN

- disallow saving empty APN form - at least `Name` must be provided,
- show `Save` button only if `Name` field is not empty,
- return to APN list window after adding/editing/deleting APN
  or setting APN to default

[EGD-6600] Add rejected call message

Adds rejected call message
instead of ended call.

[EGD-6579] Fix audio crash after playback

Fix phone crash after playback ringtone in new alarm window

Signed-off-by: Lucjan Bryndza <lucjan.bryndza@mudita.com>

[EGD-6603] Add and enable catching of OOM failures

Catch Out-Of-Memory and stack overflow in OS hooks

[EGD-6622] Add GDB to docker image

GDB may be useful for debugging problems in docker itself.

[EGD-5238] Fixed no error message on bad style

With enabled fail on first error we never got to error
printing line in style check

[EGD-5703] Fix SimCard topBar icon on Desktop

In initial design a `TobBar`'s SimCard icon with number is supposed
to display on the home screen only if there are two cards inserted.
Because of the hardware limitations (there is no way of telling if
there is a single or two cards inserted) the established consensus is
that home screen should not display SimCard widget unless it's
indication error state.

Although in the task description there is only home screen mentioned,
the behaviour was established for all `ApplicationDesktop`'s windows.

[EGD-6495] Add pause/resume/stop to MP

Added basic Pasue/Resume/Stop actions to confirm
that related Audio service operations work

Added handling of headset OK for Pause/Resume/Stop actions
while in Music Player

[EGD-6064] Add connecting and pairing bluetooth states

Pairing and connecting states are now visualized
in All devices window to inform phone user what is happening.

[EGD-5776] Replace incorrect block contact icon with the correct one

Replace incorrect block contact icon with the correct one.

[EGD-6618] Added gdb to docker

Added gdb to docker

[EGD-6617] Added option to disconnect handler in service

Till now we were only able to connect handlers to services, but
disconnect was not possible. With nullptr handler system would crash

Merge branch 'stable' - release v0.63.1

changelog: add changelog for v0.63.1

Add changelog for v0.63.1.
Fix invalid year in previous releases.
Add changelog prologue to ease the release process.

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

[EGD-6537] Create Jenkins CI

Try to fix GitHub problems by switching to Jenkins CI system.

[EGD-5748] Remake Cellular flow

This commit remakes cellular data flow
introducing full error propagation.

[EGD-6613] Audio assets tags are not displayed

When selecting ring/sms/notification sound the title from audio tags is
displayed. If tags are empty the filename is shown.

[EGD-5849] Make calculator compute previous operations

Modify calculator behavior according to PO input:
* Compute existing equation before entering next operation
* Limit digit input to 7 digits
* Start each number input from empty input

[EGD-6337] Add desktop tethering notification

This PR adds home screen tethering notification. The notifications
allows user to disconnect tethering from desktop by focusing on
the notification and pressing `KEY_ENTER`

This PR adds also home screen notifications icons in `.png` format.
Icons shall be converted to `.vpi` and used in other tasks regarding
home screen notifications.