By default, images on websites can be dragged and dropped in browsers. As we have a custom drag & drop system, this commit removes the default drag & drop behavior during the edition of a website page. In addition, this commit prevents `OdooEditor` from managing drag and drop on images that should not be dragged and dropped by the user. task-3369600 closes odoo/odoo#125151 Signed-off-by: Benjamin Vray (bvr) <bvr@odoo.com>