Add data-entity-bundle prop for better JSON:API support

Problem/Motivation

Related to ✨ Add Bundle to for Decoupled applications Active

I'm working on a build that uses this module in a decoupled setup, and it is preferred that frontend be responsible for the final rendered markup.

The site uses a transpiling method to process the markup, that has allowed for regular embedded media to render a DrupalMedia Vue component.

But the JSON:API requires the Entity Type, UUID and Bundle to load a resource. There's a patch in the related issue for the EmbedMedia plugin, but this also needs to be addressed in this module.

Steps to reproduce

Here's an example Decoupled project running in Gitpod: https://gitpod.io/#https://github.com/Decipher/druxt-experiments/tree/fe...

It doesn't have this specific module, but does have a working decoupled Wysiwyg Media embed with frontend rendering system.

Steps would be:
- Install and setup this module
- Embed a Media link
- Look at source; No `data-entity-bundle="whatever"` attribute

Proposed resolution

- Add `data-entity-bundle`

Remaining tasks

- Add `data-entity-bundle`

User interface changes

API changes

Data model changes