No Bug: Add sandbox inspector to settings debug section

[kylehickinson]

Summary of Changes

Adds a sandbox file inspector to the debug menu for inspecting the sizes. At the moment its quite simple, but we could probably expand on it to include quick look and exporting files/folders.

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue and pull request is assigned to a milestone (should happen at merge time).