ci: Expand ESLint to tests in BE packages (no-changelog) (#6147)

* 🔧 Adjust base ESLint config

* 🔧 Adjust `lint` and `lintfix` in `nodes-base`

* 🔧 Include `test` and `utils` in `nodes-base`

* 📘 Convert JS tests to TS

* 👕 Apply lintfixes

packages/nodes-base/test/nodes/FakeCredentialsMap.ts

@@ -1,4 +1,4 @@
-import { IDataObject } from 'n8n-workflow';
+import type { IDataObject } from 'n8n-workflow';
 
 // If your test needs data from credentials, you can add it here.
 // as JSON.stringify({ id: 'credentials_ID', name: 'credentials_name' }) for specific credentials