Stimulus Dropdowns
Fetch from server
When a src arg is given then, on opening, a xhr/GET request is fired to the server and the .body part of the dropdown is replaced by the result
When no block is given, no panel is created on first rendering. On opening and when a src argument is given, it finds-or-creates a panel or modal tag within body#overlays-box.
This is useful for rendering lists by turbo-stream: On first rendering, no panels or modals are rendered which saves time. When clicking on a button, it creates the modal or panel in body#overlays-box, which may be outside of the frame while no content_for would work on this point.