QUIC: improved packet and frames debug tracing. Currently, packets generated by ngx_quic_frame_sendto() and ngx_quic_send_early_cc() are not logged, thus making it hard to read logs due to gaps appearing in packet numbers sequence. At frames level, it is handy to see immediately packet number in which they arrived or being sent.

--- a/src/event/quic/ngx_event_quic_transport.c
+++ b/src/event/quic/ngx_event_quic_transport.c
@@ -1135,6 +1135,9 @@ ngx_quic_parse_frame(ngx_quic_header_t *
     }
 
     f->level = pkt->level;
+#if (NGX_DEBUG)
+    f->pnum = pkt->pn;
+#endif
 
     return p - start;