Allow branching the views after transactions were applied

[Jonas Jelten]

We need this to avoid applying the same patches in every view.

This is currently cumbersome:

• First, apply mods
• Then, create teams (each needs a View)
• Then apply the team boni patches

Currently, each View starts at the root state, so for each team, we would need to apply the patches the mods use for registration for each View of the teams.

The solution is that it is possible to "fork" a view and continue from this state with a new view.