[PP-1] Handle media image fields on page data form

Overview

✨ Save page data form values in application state with support for undo/redo Active didn't address media fields: the selected image is not stored in the application state. Selection is currently possible for newly added images. The form control to remove the selection is also missing.

Proposed resolution

See if we need to adjust or replicate experience_builder_field_widget_single_element_media_library_widget_form_alter() and/or experience_builder_preprocess_media_library_item__widget() for the page data form.