[FIX] web: editable list view regression bc031379 (9.0)

In 9.0 in some particular instances with embedded views, if:

- an x2many list view is editable,
- we go from a form view of an existing record to creating a record,
- the timings of deferred resolving are in a certain order

the x2many list view could be tought as loaded whilst in reality it is
the 'editable list view' row editing 'form view' that has been loaded.

This could cause sometimes issues after bc031379 because the onchange
computation would happen before the list view is really loaded.

This is probably an issue with the deferred system in one of the views,
but it would be rather hard and dangerous to change it.

So this fix introduce an additional test which ignore relational views
if there is an embedded view.

opw-726701
opw-726768

note: only needed for 9.0, the relational views have been changed as of
saas-11 and this issue is not present.