[EGD-5884] Added Lock Screen popup handling

Moved lock screen window to popup. Split DesktopMainWindow into
two parts (popup and regular). Added LockPhoneHandler into
ApplicationManager.

[EGD-3119] Hide InputEvent's member fields

Use the InputEvent's convenience methods to express intent.

[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-6563] Don't allow to edit exponent output in calculator

Clear the calculator input field before typing if it contains exponent
output from previous calculations.

[EGD-6527] Internationalization API unification

Single api to rule i18n
all calls to localistaion in cpp files unified
cut off ass many dependencies in i18n header as possible

[EGD-6561] Limit calculator decimals to 6 digits

Limit to 6 since our `utils::to_string(double)' function also
limits to 6 decimals.

[EGD-6561] Make calculator input testable

I got sick of manually testing calculator like a troglodyte.

[EGD-6560] Do not clear "0" on Enter in calculator

Do not treat input string "0" as erroneous.

[EGD-6498] Do not perform calculations on empty input

We do not produce an error when user calculates empty input.

[EGD-6500] Clear calculator input on # long press

Long pound press should clear input text.

[EGD-6494] Application Manager on action switch fix

Application Manager switch on Action no longer causes to
newly opened application main window switch but it
calls declared action handler.

[EGD-6347] Refactored phone modes handling in applications

PhoneModeObserver doesn't work properly in applications.
Applications have to handle the phone mode changes via AppMgr.
Phone mode and tethering handlers separated.

[EGD-6208] Add blocking phone mode changes during tethering

When the tethering is enabled, the phone mode shouldn't change,
now, any attempt ends with a notification

[EGD-6209] Tethering confirmation popup added

Provided a tethering confirmation popup.
The popup shows up once a USB cable is connected to a PC.

[EGD-5743] Added phone modes popup

Implementation of phone modes window.
Minor fixes of previous approach.

[EGD-5712] Volume popup added

There is need of popup window on volume key
pressed event. This PR handles:
Creating base popup window attached to
application desktop.
Creating volume window.
Audio key events logic implementation.

[EGD-5883] Added generic button popups attach to applications

Created structure and implementation for popup windows
attachments on button actions into applications. Moved Volume
window to fit into solution. BarGraph refactored.

[EGD-5999] Fix stack size for calculator

Set stack size to 2,5kB for calculator app

[EGD-5860] Fix build packages

Merging and cleaning cmakes requred cleaning.

Merge branch 'EGD-5737-merge-master-to-exp-lbr-fix'