Introduce new entity: class Http2::Frame with accessors like
payloadSize/type/flags/streamID etc. (they actually read
/interpret raw bytes from a frame's buffer) instead of
duplicating this functionality in reader/writer classes.
Delete defaulted members and remove explicitly defined
move ctors/operators (not needed actually).
Update auto-test ('HTTP/2 server') to use these new classes.
Change-Id: Ie3516efbd095704e212142eef9e792323678ccfa
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
4c27221295