Block Bindings: Add support for the Media & Text Block image

[Drivingralle]

What problem does this address?

At the moment the image of the media text block inside a template can be set to a fixed image or the featured image. The block is handy to style templates and would benefit for the use of bindings.

What is your proposed solution?

Enable block bindings/overrides on the media text block's media ID attribute.

[Mamaduka]

Related: #67520.

Enable block bindings/overrides on the cover block's media ID attribute.

Is this an issue for Media & Text or Cover block?

The Media & Text already allows using a featured image, via "useFeaturedImage":true attribute. See: #51491.

[Drivingralle]

@Mamaduka I meant the media text block. Have fixed my typo.

My goal is to overwrite the image (ID) of the media text block placed inside a template via a post meta field.