qlog: split serializiation and event definitions, remove logging abstraction (#5356)

* qlog: implement a Trace and a Writer struct

* qlog: rename Trace to FileSeq

* split qlog trace writer and QUIC qlog events into separate packages

* use the new qlog.Recorder instead of the logging.ConnectionTracer

codecov.yml

@@ -9,8 +9,6 @@ coverage:
     - internal/utils/linkedlist/linkedlist.go
     - internal/testdata
     - internal/synctest
-    - logging/connection_tracer_multiplexer.go
-    - logging/tracer_multiplexer.go
     - testutils/
     - fuzzing/
     - metrics/