[CP-1448] Add storage info to device info endpoint

DeviceInfo endpont now contains information such as:
deviceSpaceTotal - total storage space on the device
systemReservedSpace - storage space on the device
reserved for the OS
usedUserSpace - storage space on the device used
for user files on the user partition

[MOS-000] Update PR template

Updated PR template to have reminder about changelog entry

[MOS-657] Fix contacts list order

Fix of the issue that contact group
letter appeared below the
corresponding contacts when
navigating up.

[BH-1552] Minor power optimization

Switched off temperature sensor and
its driver.
Minor GPIO pads configuration tweaks.

[MOS-647] Fix AVRCP volume control

Fix of the AVRCP volume control.
Minor code cleanup.

[BH-1542] Fix TimeFixedWidget encapsulation

*DigitsContainer extracted as testable module
*Getters removed from TimeFixedWidget

[MOS-613] Fix keyboard doesn't respond

Now the keyboard driver is checking the result of i2c
transmission and we get an error code if something fail.

[BH-1542] Stabilize the clock position

Third digit fix

[MOS-649] Rename confusing method

Rename confusing method

[MOS-000] Update changelog

Update release date

[CP-1453] Update test script for file system endpoint

Add test for listing files and their size in a specified path.

[MOS-638] Fix poor phone responsiveness

Sometimes it took a long time to redraw
the screen with the USB cable unplugged.

[CP-1454] Add file size to the list of files in specified path

Next to each of the files listed in the file list in the path
specified in the request is now displayed its size.

[MOS-000] Update README

Updated changelog entry in readme

[MOS-000] Add changelog

Added changelog

[BH-1537] Statistic frontend

Added integration of statistics model,
presenter and widget.

[BH-1538] Stats info widget

Created statistics info widget.

[MOS-645] Fix Mudita Center synchronization fail

Sometimes the user was unable to connect
to the Mudita Center due to sync errors

[MOS-421] Add state refresh when BT automatically turns off

Added code to update BT power state
when it automatically turns off due
to inactivity.

[MOS-598] Improved keyboard responsiveness

Add sentinel that increases and hold the CPU frequency
after a button press event