MINOR: mux-quic: interrupt qcc_recv*() operations if CC scheduled

MINOR: mux-quic: interrupt qcc_recv*() operations if CC scheduled

Ensure that external MUX operations are interrupted if a
CONNECTION_CLOSE is scheduled. This was already the cases for some
functions. This is extended to the qcc_recv*() family for
MAX_STREAM_DATA, RESET_STREAM and STOP_SENDING.

Also, qcc_release_remote_stream() is skipped in qcs_destroy() if a
CONNECTION_CLOSE is already scheduled.

All of this will ensure we only proceed to minimal treatment as soon as
a CONNECTION_CLOSE is prepared. Indeed, all sending and receiving is
stopped as soon as a CONNECTION_CLOSE is emitted so only internal
cleanup code should be necessary at this stage.

This should prevent a registered CONNECTION_CLOSE error status to be
overwritten by an error in a follow-up treatment.

This should be backported up to 2.7.