Feature Request

• Yes, I reviewed the contribution guidelines.

Describe your use case and the problem you are facing

There's currently no way of completely clearing the oembed cache. This is for example useful after one has added a oembed_dataparse filter to modify the HTML.

Describe the solution you'd like

I'd propose adding an cache clear-all command.

The quick and dirty version is to run DELETE FROM wp_posts WHERE post_type = 'oembed_cache' and DELETE FROM wp_postmeta WHERE meta_key LIKE '_oembed_%'.