[#128 H] Trips

[tillwenke]

relates to bopjesvla#128

I only introduce the necessary db changes here and basic functionality to interact with and create trips.

Everything beyond that should be done in a follow-up UX PR.

[bopjesvla]

Everything beyond that should be done in a follow-up UX PR.

Risky business. Maybe collaborate with someone on this? UX things don't tend to happen on their own, and it's easier to implement something from scratch than to update someone else's reference implementation.

[leon-wbr]

This PR will take a little bit longer to merge, I'd like to join in on this and contribute to it. Alright for you, @tillwenke?

[tillwenke]

This PR will take a little bit longer to merge, I'd like to join in on this and contribute to it. Alright for you, @tillwenke?

I believe this pr is pretty self-contained and large enough. I d rather complete it first and everything else can be done in a follow up pr. the current functionality is minimal but still sufficient (by that I mean anyone using it as it is wont do any harm playing around with it) - we will not draw the users attention towards /trips yet.

This enables us to play around with and test it in production e.g. to see how we like the automatically generated trips - it is easiest to understand this with your own reviews liked to your account in prod. If you have to test it locally I can recommend creating a user "Chris9012"

I opened a follow up pr here #33