MINOR: mux-quic: refresh timeout on frame decoding

MINOR: mux-quic: refresh timeout on frame decoding

Refresh the MUX connection timeout in frame parsing functions. This is
necessary as these Rx operation are completed directly from the
quic-conn layer outside of MUX I/O callback. Thus, the timeout should be
refreshed on this occasion.

Note that however on STREAM parsing refresh is only conducted when
receiving the current consecutive data offset.

Timeouts related function have been moved up in the source file to be
able to use them in qcc_decode_qcs().

This commit will be useful for http-request timeout. Indeed, a new
stream may be opened during qcc_decode_qcs() which should trigger this
timeout until a full header section is received and qcs instance is
attached to sedesc.