Have RST_STREAM & STOP_SENDING do expected closes for IETF QUIC (V99)

This change connects up the RST_STREAM and STOP_SENDING code so that
- when a RST_STREAM is sent, the sending node closes the stream for write only.
- when a RST_STREAM is received, the receiving node closes the stream for read only.
- when a STOP_SENDING is received, the node responds with a RST_STREAM and
  closes the stream in the write direction (from the perspective of the node
  receiving the STOP_SENDING)

Note that this implementation will send a RST_STREAM + STOP_SENDING, each causing the
stream to be closed in one direction. The two together cause the stream to be closed in
both directions, effecting a full close on the stream.

n/a, only for Version 99/IETF QUIC and controlled by the v99 flag

NO_BUG=Feature

Merge internal changes: 230929605, 233058905

R=rch@chromium.org

Change-Id: I622dff1297efc90971f025e70c574dcb6f68bbe2
Reviewed-on: https://chromium-review.googlesource.com/c/1461077
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Commit-Queue: Frank Kastenholz <fkastenholz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631814}
30 files changed