When able to be parsed, store the created date for a video file from meta,
since this is useful separately from the dates on the file itself.
Introduces `wp_get_media_creation_timestamp()` to read the timestamp from
getID3 and a `wp_read_video_metadata` filter analogous to
`wp_read_image_metadata`.
Fixes#35218.
Props stevegrunwell, joemcgill, desrosj, blobfolio, mikeschroder.
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