Fix incorrect import of isEmpty

This caused "Patients are automatically triaged without any personnel on the map" #623

shared/src/models/patient.ts

@@ -9,8 +9,8 @@ import {
     IsBoolean,
     IsString,
     MaxLength,
-    isEmpty,
 } from 'class-validator';
+import { isEmpty } from 'lodash-es';
 import { uuidValidationOptions, UUID, uuid, UUIDSet } from '../utils';
 import { IsLiteralUnion, IsIdMap, IsUUIDSet } from '../utils/validators';
 import { IsMetaPosition } from '../utils/validators/is-metaposition';