[FIX] web_editor, website, *: editor `notify` method must be synchronous

* website_form

Some technical explanations:

The method became async because the `setTarget` call which was in there
became `async` since it performed an UI update. As this method being
async is a problem with some snippets, it is best to keep it synchronous
for now. For this, the UI update in `setTarget` is removed and becomes
the responsibility of the caller. Nothing relied on it except one code,
which is solved by calling `onFocus` before the UI update which occurs
on focus, as it is already the case in master.

closes odoo/odoo#44850

X-original-commit: 53bba0660237abbcadc9675fd89ec94a2a31e130
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>