Add flag cache in internal state type
Add helper for setting flags of a transaction
We can go to the next state by using the key map here
Add transition from parsed flags key to flags map and back
Add execution flag parsing
Add transition from FLAGS_MAP to FLAGS_EXEC state

via FLAG_EXEC flag.
Add message finalization
Add helper for setting name of transaction
Add key for register flag
Add state transition from map to register flag
Add name cache variable in deserializer state type
Add register flag support
Add simple flag test