Separate the TargetedAction `targets` into preprocessed extra arguments
Separate the TargetedAction `targets` into preprocessed extra arguments

This normalizes all extra arguments and lets us preprocess some of them.
We use it to preprocess the `card` argument to Summon, which lets us
reuse the argument when broadcasting the event.

amw2104/fireplace,butozerca/fireplace,jleclanche/fireplace,amw2104/fireplace,Meerkov/fireplace,smallnamespace/fireplace,oftc-ftw/fireplace,beheh/fireplace,oftc-ftw/fireplace,smallnamespace/fireplace,Ragowit/fireplace,Meerkov/fireplace,liujimj/fireplace,butozerca/fireplace,NightKev/fireplace,liujimj/fireplace,Ragowit/fireplace