Fix path selection choosing a to big step, since the next step
was determined by the moving range and not the actually available
movement tiles.

Fix generating a target for the AI by introducing a dummy action
to support "enemy" target constraints.

Do not allow to declare slow play actions in the client.
Fix the slow action check in the game state.

This allows to not use the internal game state directly from client
code.

This is done to propagate the chosen variadic play cost to the
card implementation.

All TriggeredAction are passed in the wrapper action
DeclareTriggeredActionsAction to the controller of the triggers.
It is expected to receive an ordered list back from the user
again wrapped in a DeclareTriggeredActionsAction.
The triggered actions will be declared in from first to last.