fix crash when printing with misconfigured printer

fixed white screen problem on loading app with no internet connection

~ fixed subtitle for English and German on the App Store

+ improved App Store description and screenshots

+ integration with new backend endpoints

- added tutorial videos

- added sound notification when orders are created or updated

- fixed opening of external urls in separate Safari app window

- fixed printing for Wifi and Ethernet TCP thermal printers

- minor fixes in the UI

- fixed bug where New Order was not doing anything

- Toegevoegde tabellen te kunnen bekijken
- Toegevoegde rapporten te bekijken
- Toegevoegde afdrukken met ethernet en wifi thermische printers

improved translation for Italian and Spanish