tests: update dawn tests for recent changes
tests: update dawn tests for recent changes

Also includes some new tests for the multikeyfile case.

urbit/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,ngzax/urbit