Expose oEmbed provider URL setting in the Media configuration form

Problem

In Russia the URL https://oembed.com/providers.json, as well the whole website https://oembed.com/ is blocked by providers by Roskomnadzor.

Media module in 8.6. is have setting media.settings.oembed_providers_url which used to parse available and actual oEmbed providers for Media. e.g. for Remote video media type.

In our case, Drupal can't access this JSON file and Remote video can't be created at all. Drupal throws error and thats it.

If I trying to add Remote Video on Simplytest, with same URL, this works fine as expected.

Solution

The URL of the provider database is already a configuration setting. Let's expose it in the Media module's configuration form (along with good help text and validation) so that site builders can easily use an alternate provider database.

Remaining Tasks

Write a patch, write tests, bikeshed the help text so it's nice and clear, commit.