Issue #3314722 by nginex: Create a Cloudinary media source instead of a separate media type.

Closes #3314722

1. Adds a new media source for cloudinary. Single source for all resource types.
2. Deprecates old way of using the module and media. It's still supposed to be working (there is backward compatibility) but will be removed from next major release.
3. Defines a new field widget, field types, and field formatters.
4. Integrates with core field formtters.
5. Removes video_embed_field dependency.
6. Rewrites logic of generating external url for the cloudinary steam wrapper.