I'm not sure why we decided to have a boolean here, but apparently that wasn't the correct behaviour. According to HW tests, the Software Keyboard simply displays the default text when the button text provided is empty (**not necessarily all zero**). For example, if you set a text for one of the buttons and leave others empty, the button you set will have your text, while others will have their default texts. Removed the boolean and updated frontend code to make it correct.
* swkbd: Fix a bug where clicking Cancel hangs the game
The text is validated in `Finalize`. If the validation fails, an error is returned and the applet is not actually finalized. This can result in hangs.
This is usually not a problem as the frontend is expected to validate the text passed to `Finalize`. However, when the user clicked on `Cancel`, the text is ignored and the frontend won't do any validation. Therefore, we should skip the validation here as well.
Also fixed a potential data race. All these functions should now be called on the same thread
* Address review comments
Renamed the fields
Remove close button
* Addressed comments and removed the applet interface
* swkbd: address @lioncash's comments
* core: more fixes
** Moved registered_swkbd to System
** Removed an usused virtual
** Removed functionality of DrawScreenKeyboard
** Removed src/core/settings.h change
* swkbd: address @lioncash's 2nd review
* swkbd: update logging macro
* QtKeyboard: Make dialog modal and hide help
