[Formulus] Data generation handling

[r0ssing]

Component

• formulus (React Native mobile app)
• formulus-formplayer (React web app)
• synkronus (Go backend server)
• synkronus-cli (Command-line utility)
• Documentation
• Other (please specify)

Bug

When opening Formulus the first time after an installation and sync'ing with a Synkronus instance that has a data generation > 1 (i.e. it has at some point been reset), you will get a scary warning about wiping the device.
We should handle this scenario in a way, such that Formulus simply sets the local data generation to be that of the server on connect (especially since there is no data on the device at this point).