[IMP] web_editor, *: change image cropping from modal to inline widget

*: base

Previously, cropping an image was done inside of a modal window, turning
it into an inline widget makes the editor feel more integrated and
allows you to better see the result of cropping directly in the page,
it's also less intrusive to the user's edition workflow.

At the same time, the way cropped images are saved was refactored to use
the new original_id field on ir_attachment, as the old system was
creating problems.

Part of https://github.com/odoo/odoo/pull/51517
task-2192755