bulljobs don't respect common headers

added the common truth (user-agent.ts) to all bulljob services

src/lib/integrations/transmission.service.ts

@@ -4,6 +4,7 @@
  */
 
 import axios, { AxiosInstance } from 'axios';
+import { RMAB_USER_AGENT } from '../utils/user-agent';
 import https from 'https';
 import path from 'path';
 import { DOWNLOAD_CLIENT_TIMEOUT } from '../constants/download-timeouts';
@@ -109,6 +110,7 @@ export class TransmissionService implements IDownloadClient {
       baseURL: this.baseUrl,
       timeout: DOWNLOAD_CLIENT_TIMEOUT,
       httpsAgent: this.httpsAgent,
+      headers: { 'User-Agent': RMAB_USER_AGENT },
     });
   }