BUG/MEDIUM: quic: limit reject after MUX closure to once per stream

BUG/MEDIUM: quic: limit reject after MUX closure to once per stream

This patch is a follow-up to the previous one. The objective is to limit
the number of allocated frames after MUX closure for STREAM handling.

Ensures that each stream is closed only once. This is performed by
incrementing the ID stored in the quic_conn structure each time a stream
is rejected. If a non-contiguous ID is received, all intermediary
streams are rejected as well.

Along with the previous patch which ensures that stream IDs higher than
the flow control limit cause an immediate closure, this guarantees that
frame allocation for stream rejection after MUX closure remains low and
bounded.

This must be backported up to 2.6 after a period of observation.