Background image on sections and blocks

Proposed resolution

For blocks:

To cover both blocks in Layout Builder and in Block layout, use the same logic as ui_styles_block and ui_styles_layout_builder.

Use https://www.drupal.org/project/media_library_form_element for the form element.

For sections:

- wait for #3449390: [5.1.0] Create components for grid management
- add a new setting to section components to be able to select a media image?

OR

if already taking inspiration from ui_styles_layout_builder for blocks in Layout Builder, also do the same logic as the sections parts of ui_styles_layout_builder.

So no need to override layouts provided by ui_suite_bootstrap, and will be able to apply to any components used as layouts.

TODO:
- UI Patterns attributes plugin source
- Need to be able to handle background image on block contents by adding a media field on the block type and so view displays could use it with tokens.