MINOR: mux-quic: support glitches

MINOR: mux-quic: support glitches

Implement basic support for glitches on QUIC multiplexer. This is mostly
identical too glitches for HTTP/2.

A new configuration option named tune.quic.frontend.glitches-threshold
is defined to limit the number of glitches on a connection before
closing it.

Glitches counter is incremented via qcc_report_glitch(). A new
qcc_app_ops callback <report_susp> is defined. On threshold reaching, it
allows to set an application error code to close the connection. For
HTTP/3, value H3_EXCESSIVE_LOAD is returned. If not defined, default
code INTERNAL_ERROR is used.

For the moment, no glitch are reported for QUIC or HTTP/3 usage. This
will be added in future patches as needed.