With the recent control panel refactoring, abstract actions had to be
adapted. The base import action is actually quite
complicated, it relies on introspection and is fragile. With this
commit, I attempt to make it work again. The main issue is that now,
the root of the abstractaction is a div, which contains the root of the
content template, so most of the code was assuming that the $el of the
import action was the form tag, and not a parent.
Note that there are no meaningful tests for import actions, because
testing iframes are tricky.
closesodoo/odoo#29421
Géry Debongnie
6c1445b24e