[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5090] Add Brownout GUI window

Gui window will appear due to brownout
event. System shutdown will be also called.

[EGD-4960] registerVariableChange moved to Init section of apps

[EGD-4960] Settings Interface added parameter do distinguish global/app settings
[EGD-4960] global/local setting determined by enum value, unregister all variables in one call, ut updated
[EGD-4960] SettingsScope usage in SettingsMessages

[EGD-2501] Add gsm powerdown due to battery

Gsm model power state maintenance based on battery level.

[EGD-4968] Change GUI service to optimize flow and memory management

Gui and Eink services refactor.
Displaying frames performance optimization.
Critical resources management.

[EGD-5026] Change Eink service code structure

Refactor.

[EGD-4694] Add CPU frequency shift mechanism

The CPU frequency changes automatically which saves energy

[EGD-4898] Add GUI for Custom MMI messages- call forwarding

Visitor framework for displaing MMI messages.
GUI for call forwarding custom messages.

[EGD-4856] Add Custom MMI message

Adds custom MMI respponse mesage.
It will be used by MMI response window to translate message.

[EGD-4925] Change new filesystem handling implementation in module-gui. (#1193)

Due to vfs deprecation there is need to remove all vfs calls from code. This PR covers module gui. There are some modifications in other modules included which are necessary because of build system issues.

[EGD-4914] input and display languages connection to settings problem… (#1188)

* [EGD-4914] input and display languages connection to settings problem solved

Merge branch 'master' into stable

[EGD-4150] Change filename i18 to i18n (#1108)

Change filename of internationalization files from i18 to i18n.

I18n should stand for internationalization, not i18. That's why I changed in 'module-utils' name of the folder 'i18' and both .cpp and .hpp files to 'i18n'.

[EGD-3572] SettingsTable exchanged to settings::Settings (#968) (#1044)

[EGD-3572] Application has an instance of Settings - removed from derived apps
[EGD-3572] Application is the owner of Settings handling for its windows/widgets
[EGD-3572] Settings header moved to service-db public section

[EGD-4167] Add n display languages loaded from files (#1047)

[EGD-4423] Added MMI convertible to action messages. (#1087)

* [EGD-4423] Added MMI convertible to action messages.

* [EGD-4423] Fixed message type.

* [EGD-4423] Review applied.

* [EGD-4423] Unneded message removed, restored cellular log blocking.

Co-authored-by: Kuba Kleczkowski <dd>

[EGD-4155] Created a code example of possible implementation of generic data pack for actions. (#957)