add module for func_key_dest_park_position
add module for func_key_dest_features
add business logic for managing park position func keys
add business logic for parking func key
fix bug in func key deletion

Column names were wrong in a few places, which caused
bugs when deleting a func key of type forward or park position
disable destination on parking func key

destination is never used when parking a call
fix constant name
Merge branch '5200_func_key_parking'