Add support for collecting user name on FIM (File Integrity Monitoring)

**Describe the enhancement:**
FIM module collect the user name info and visualize in user.name field on both Linux and Windows

**Describe a specific use case for the enhancement or feature:**

User/customer has FIM requirements due to they are FSI industry. For the compliance requirements, customer needs to monitor the critical path to understand what has been changed, **who does the change**, who is the file owner and in which platform etc..

Most of features our FIM integration can support except the **user name**

This make the FIM module is not quite out-of-the-box to replace other existing solution. This will be our added value to talk about Elastic platform when comes to security compliance.