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/system-config/system-config.core.ts

@@ -72,6 +72,7 @@ export const defaults = Object.freeze<SystemConfig>({
       modelName: 'buffalo_l',
       minScore: 0.7,
       maxDistance: 0.6,
+      minFaces: 1,
     },
   },
   map: {