Add logging for cloud based connectors

[moxarth-elastic]

Part of #2299

This PR includes some cloud-storage based connectors as follows:

1. Box
2. Dropbox
3. Google Cloud Storage
4. OneDrive
5. S3

This is a follow up PR of #2329

Drive folder for log files with DEBUG log_level: https://drive.google.com/drive/folders/13-P99PjgjFdjI9hrmPsuhNst6Kdu5C0-

Checklists

Pre-Review Checklist

• this PR does NOT contain credentials of any kind, such as API keys or username/passwords (double check config.yml.example)
• this PR has a meaningful title
• this PR links to all relevant github issues that it fixes or partially addresses
• if there is no GH issue, please create it. Each PR should have a link to an issue
• this PR has a thorough description
  - [ ] Covered the changes with automated tests
• Tested the changes locally
• Added a label for each target release version (example: v7.13.2, v7.14.0, v8.0.0)

[moxarth-elastic]

Buildkite test this