Introduce Core Widget: Audio

[melchoyce]

This ticket introduces a new core widget for displaying audio.

See 32417#comment:136 for history.

Keep an eye on ​https://github.com/xwp/wp-core-media-widgets for development.

Is this only for locally hosted audio, or would it handle a URL?

Replying to joyously:

Is this only for locally hosted audio, or would it handle a URL?

Ideally, it would handle both a locally hosted audio file and a URL. I think we should work on splitting it out of @gonom9's patch into a standalone widget, and then evaluate whether it makes sense to handle a URL in v1 or wait for a v2.

In 40640:

Widgets: Introduce media widgets for images, audio, and video with extensible base for additional media widgets in the future.

The last time a new widget was introduced, Vuvuzelas were a thing, Angry Birds started taking over phones, and WordPress stopped shipping with Kubrick. Seven years and 17 releases without new widgets have been enough, time to spice up your sidebar!

Props westonruter, melchoyce, obenland, timmydcrawford, adamsilverstein, gonom9, wonderboymusic, Fab1en, DrewAPicture, sirbrillig, joen, matias, samikeijonen, afercia, celloexpressions, designsimply, michelleweber, ranh, kjellr, karmatosed.
Fixes #32417, #39993, #39994, #39995.

In 40647:

Media: Clean-up some MediaElementJS CSS: no more needed after [40642].

See #40707, #32417, #39994, #39995, #30281.

In 40784:

Widgets: Use "Add Audio" for button in Audio widget instead of generic "Add File".

Props juhise.
See #39995.
Fixes #40797.

In 40812:

Widgets: clarify some context information for translators.

Props Italian polyglots team.
Amends [40640].
See #32417, #39993, #39994, #39995.

In 40813:

Media: Remove core embedding support for WMV and WMA files since MediaElement.js has discontinued supporting them.

Plugins may continue to add embedding support for these file formats by re-adding them via the wp_video_extensions and wp_audio_extensions filters while also implementing fallback rendering routines via the wp_video_shortcode_override and wp_audio_shortcode_override filters.

See #39994, #39995.
Fixes #40819.

In 40836:

Widgets: Ensure that audio and video files appear in media library browser upon upload.

Props timmydcrawford.
Amends [40640].
See #32417, #39994, #39995.
Fixes #40803.