Fix: Back button on top of screen

The back button on top of screen notably in travel participant list does not goes to the previous screen in the navigation, but to the previous screen seen.

Acceptance criteria:

The back button on top of the screen should go to the travel edit screen and then the back button should go to the list of travel.
No UI should be changed

TravelPouch / travelpouch

Fix: Back button on top of screen #214