feat(web): add setting for minimum face count for face detection (#4128)

* feat: add setting for minimum face count for face detection

Adds the minimum face count setting to the web interface to
circumvent detection of strangers and random background people
if desired.

* fix: codestyle, remove max for face count

server/src/domain/facial-recognition/facial-recognition.service.spec.ts

@@ -205,6 +205,7 @@ describe(FacialRecognitionService.name, () => {
           enabled: true,
           maxDistance: 0.6,
           minScore: 0.7,
+          minFaces: 1,
           modelName: 'buffalo_l',
         },
       );