Allow to propagate errors in order to handle them acordingly.
Use playerNotifications by value to reduce the amount of allocations.
Add session managment playerNotifications.
Support marshalling notifications to plain text.

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.

* fix a lot of target and action bugs
* check target selection before adding it to the prompt
* use the store view for stores on the map
* fix card highlighting in CardGrid
* Only prompt for Upkeep-/DiscardActions if appropriate
* Add helper for areaEffects granting new FullActions
* Add Target() helper selecting the first target to the Action interface
* Fix BuyAction and DiscardAction targets
* Remember the stores a player has seen