Add Vimeo support

[steveoliver]

This adds support for Vimeo videos.

TODO/Discuss:

• Configurable width/height? Where do these config options get set?
• Thumbnail -- maybe we want to get the largest thumbs possible (I'm currently getting medium)

[slashrsm]

Missing newline.

[steveoliver]

newline added.

[slashrsm]

Configurable width/height? Where do these config options get set?

We are missing this piece at the moment I believe. We should think how to introduce that.

Thumbnail -- maybe we want to get the largest thumbs possible (I'm currently getting medium)

Yup, that makes sense.

[steveoliver]

I believe commit steveoliver@d7bc032 does the injection you're talking about? Also, not sure how defaultConfiguration() from your captured code comment is affected. What should I do with defaultConfiguration()?

[steveoliver]

@slashrsm, I see that you must not have meant to cite the defaultConfiguration() method ... you selected everything up until that line. So I think we're good on the injection of the token.

However, the configuration of the token, I think we should show an alert and way for administrators to configure the API key/token(s), maybe in the UI? What's the way to do this in D8, would you say?

[slashrsm]

Yup, injected token now looks OK.

defaultSettings() are respected in VideoProviderBase. Problem at the moment is that there is no way to override that via UI. You can do it when initializing video provider plugin, but that is not what we really want. The best solution would be to expose this configuration on media type configuration page. This is out of the scope of this PR of course.

As far as it goes about access token I'd create a standalone configuration page where we would be able to set this.