Core: Improve Cleanup Temporary Files in Chipmunk Home Directory

[AmmarAbouZor]

This PR closes #2137

It improves cleaning up the temporary files (Logs and attachments) generated by an observe session with the following changes:

• Cleanup function for individual sessions is called when the session is dropped instead of calling it explicitly, ensuring that it will be called even on panics or in integration tests.
• Extend cleanup function for individual sessions to remove the attachments besides removing the main log file.
• A general cleaning up function to scan the temporary directory in Chipmunk and remove all files and directories that are older than two months. This function will be called on start of Chipmunk and will run on a separate thread to avoid blocking the initialization of the app on cleaning up huge temporary directory