MEDIUM: proto_htx: Add HTX analyzers and use it when the mux H1 is used

MEDIUM: proto_htx: Add HTX analyzers and use it when the mux H1 is used

For now, these analyzers are just copies of the legacy HTTP analyzers. But,
during the HTTP refactoring, it will be the main place where it will be
visible. And in legacy analyzers, the macro IS_HTX_STRM is used to know if the
HTX version should be called or not.

Note: the following commits were applied to proto_http.c after this patch
      was developed and need to be studied to see if an adaptation to htx
      is required :

  fd9b68c BUG/MINOR: only mark connections private if NTLM is detected