`facetFilter` in associations endpoint still operating with OR instead of AND

Describe the bug When selecting two facet categories in the new PPP functionality, they still behave with an OR operator instead of an AND. We agreed to move to an AND and thought we had implemented it but something didn't work as expected.

Observed behaviour When associations with 1 entity are filtered with specific filter, 1 record is returned

query DiseaseAssociationsQuery {
  disease(efoId: "EFO_0001421") {
    id
    name
    associatedTargets(
      page: {index: 0, size: 50}
      orderByScore: "score"
      enableIndirect: true
      facetFilters: ["hScOK5ABRHpy-SjeK0qR"]
    ) {
      count
    }
  }
}

{
  "data": {
    "disease": {
      "id": "EFO_0001421",
      "name": "liver disease",
      "associatedTargets": {
        "count": 1
      }
    }
  }
}

When adding a second filter, we would never expect more than one record (0 in this case) in and AND scenario...

query DiseaseAssociationsQuery {
  disease(efoId: "EFO_0001421") {
    id
    name
    associatedTargets(
      page: {index: 0, size: 50}
      orderByScore: "score"
      enableIndirect: true
      facetFilters: ["hScOK5ABRHpy-SjeK0qR", "zNAfK5ABRHpy-SjeepSg"]
    ) {
      count
    }
  }
}

We instead get 877 + 1 records:

{
  "data": {
    "disease": {
      "id": "EFO_0001421",
      "name": "liver disease",
      "associatedTargets": {
        "count": 878
      }
    }
  }
}

Expected behaviour The same scenario above should return 0 records as the 2 sets 877 and 1 do not overlap.

Additional context @mbdebian has pinpointed the one line in the API code that might require a change. He can provide additional detail

opentargets / issues

`facetFilter` in associations endpoint still operating with OR instead of AND #3356