[EGD-3315]Review: style fixes

[EGD-3315]Review: minor changes

[EGD-3315]Review changes: EventReminderWindow - localized date and time; unit tests for SelectFirstUpcoming query

[EGD-3315]Review changes (minor)

[EGD-3315] Main functionality: DB queries, timers processing, base classes for future use

[EGD-3469] ServiceTime - start

[EGD-3469] Rework DB

EGD-4098 Call rework

[EGD-4095] added DeveloperMode endpoint

[EGD-3506]: unittest fixes

[EGD-3506]: review fixes

[EGD-3506]: removed stale include from update window

[EGD-3506]: removed delayed reset

[EGD-3506]: removed filesystem access from the update window

EGD-3506: translations (en) for update window

style changes

added screenshots

[EGD-3506] Review fixes:
- removed c-style casting
- moved all types to updateos:: namespace
- removed stale code

More info while updating, removed the icon
switched to all text.

[EGD-3506] Update now running and rebooting after update process