Views blocks/attachments with facet search do not respect search

@john.oltman and @attisan I tested the patch from #16 and it worked partially. If the result exists in both View and Attached View, the facet shows the filter option and filters considering the two parts. But if the filter has an option that only has results for the view, the facet filter option is not shown.
To add more information I'll give a real example: I have a view with a Live event list, and an Attached View with a Recorded event list.
If both lists have events in the French language, the filter option French appears and works for both. If the French language is only present in the attached view from the Recorded event list, the filter option is not shown to me because the rule from facet settings that handle the empty filter result behavior is just considering the View, not the Attachment.

Can someone help me with this? I couldn't go further than this yet.

Same problem as Samuel ( #20 ) here, someone can help?

concerning #20.

For building facet items, we need 1 single query to retrieve the possible filter values.
Since you have different filters in your attachment, that wont technically be possible as these are 2 different queries to retrieve your resultset.

This is something which facets will probably never support, as it will get complicated very fast if we merge filters from different sources.

Patch from #16 works fine for my use-case, where the attachment renders the first result in a different layout (and other results have offset 1)

This looks great, but I think we should probably add a test or it also?

1. The views Facets display extender needs a config schema. See the metatag module for a reference: https://git.drupalcode.org/project/metatag/-/blob/8.x-1.x/metatag_views/...
2. Needs a test per #23

Any more updates on this? I'm looking at controlling an attachment map on a views page I have built and for facets to control both the page and the attachment map.