there was a long-standing buggy workaround, whereas in stream-mode, when
there was no response yet to query from, a synchronous request would be
fired. This would break when under event streams, so we had to document
this as "make sure that...".
This fixes it by implementing a general session API convention, which
separates the step of sending the requests, from waiting for its
receival. And, given that the request knows when the response is
available, we can actually "tick until response".
This might be used in the future to refactor the way we handle the
responses, which buffer the full payload by default, instead of reading
from the connection at will.
