Active facet items don't shown if no other items present in the facet

Problem/Motivation

In the issue 📌 Always show active facet items Active there a feature was implemented to always show items that are selected in the facet, regardless of the value count. But this feature does not work if no other items are present in the facet.

Steps to reproduce

1. Create a dataset with two multi-choice facets (facet1 and facet2) and a page showing the items with exposed facets.

2. Check facet filter items with two items selected in the facet1 (facet1-item1, facet1-item2), and one item selected in the facet2 (facet2-item1), but in the facet2 - the item facet2-item1 should be in match with only one item from the facet2-item1, and no other items from the facet2 should match the chosen items.

3. Uncheck the facet2-item1 and apply the form.

Expected result:
The selected item facet2-item1 should be kept in the facet2 list with one selected (active) item, even if the count of all items is 0.

Actual result:
The selected item facet2-item1 disappears from the facet2, and facet2 fully disappears, because all other items have count = 0.

Proposed resolution

We need to handle this case right, and show the active items even if no other items are present in the facet.