The largest part of the code deals with the start of a response. Moving
this into a subfunction makes the function clearer as the switch statement
inside a switch statement is removed.
By processing the packets one at a time, the reply state is updated
correctly regardless of how many packets are received. This removes the
need for the clunky code that used modutil_count_signal_packets to detect
the end of the result set.
If a result consists of only OK packets, they would be processed
recursively which most of the time leads to a stack overflow. This can be
prevented by consuming all OK packets in the result in one go.
By splitting the processing and state querying into two separate
functions, the result can be inspected multiple times without triggering
the result processing.
