Add some missing media types in external terminologies

<codeset issuer="IANA" openehr_id="media types" external_id="IANA_media-types"> Doesn't include types used today like: "image/jp2", "video/H264", "video/mp4", "video/ogg", "video/mpeg", "audio/mp4", "audio/ogg", "audio/vorbis", "audio/mpeg3" See https://github.com/openEHR/terminology/issues/6