feat: implement QuestionBank CRUD with pagination and template query

- Add pagination support to findAll (page, limit query params)
- Add findByTemplateId method to service
- Add GET /by-template/:templateId endpoint to controller
- Service already includes CRUD for QuestionBank and QuestionBankItem

server/src/elasticsearch/elasticsearch.module.ts

@@ -0,0 +1,10 @@
+import { Module, forwardRef } from '@nestjs/common';
+import { ElasticsearchService } from './elasticsearch.service';
+import { KnowledgeGroupModule } from '../knowledge-group/knowledge-group.module';
+
+@Module({
+  imports: [forwardRef(() => KnowledgeGroupModule)],
+  providers: [ElasticsearchService],
+  exports: [ElasticsearchService],
+})
+export class ElasticsearchModule {}