ci: Enable Prettier for /nodes-base (n8n-io#3315)

* ⚡ Extend `.prettierignore` patterns

* 🎨 Apply Prettier to `/src` and `/test`

* 🎨 Update `.prettierignore`

* ✏️ Group dirs with same nesting level

* ✏️ Alphabetize credentials

Author: ivov