Make it so file tree doesn't reload on upload/delete

What does this MR do and why?

We no longer reset the file tree after a file is uploaded or deleted. #24 (closed)

2023-01-29_12-30-50
This MR also adds feedback to the file uploader, showing completed uploads

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• Have you checked this doesn't interfere/conflict/duplicate someone elses work?
• Have you fully tested your changes?
• Have you resolved any lint issues?
• Have you assigned a reviewer?
• Have you applied correct labels?