This commit adds several improvements and overall changes the way
draggable builders can be built, adding some helpers to temporary
manipulate DOM elements during drag sequences and making some changes
on the way drag callbacks are handled.
The current implementations of draggable hooks built with this feature
have been adapted.
The drag test helpers have also been reviewed to more accurately
mimick real-life scenarios and allow for more flexiblity (i.e. moving an
element to a certain point during the drag sequence before being
dropped).
Part-of: odoo/odoo#110819
Co-authored-by: Julien Mougenot <jum@odoo.com>
Co-authored-by: Bruno Boi <boi@odoo.com>
