wireprotov2peer: add TODO about streaming responses
This is a pretty big deficiency in the current implementation.
We don't want to forget about this.
Differential Revision: https://phab.mercurial-scm.org/D4435
tests: update relnotes test for actual output
I'm unclear why I didn't see this before but I consistently see it
now. In any event, it doesn't appear to be a regression, so let's just
bake it into the test.
Differential Revision: https://phab.mercurial-scm.org/D4463