The web planner specified no language for frontend so the website
planner on the frontend was never translated.
This commit add a specialized fallback for this use case so the planner
on the website is in the language of the current user.
The code is the same that get_context from web_editor.base but requiring
that would possibly adds delays (for dom_ready) that we don't want.
note: this is for 9.0 up to not including 11.0, in 11.0 another solution
is used and in master a bigger change is being worked on.
opw-781727
fixes#20829closes#21004
Nicolas Lempereur
be5950e429