feat: Improve archived item upload UX

[SuaYoo]

Resolves #3253

Changes

• Allows users to continue using application while an upload is in progress, including uploading another WACZ file
• Fixes not being able to open upload form multiple times after closing out of form without saving
• Refactors upload client API to clean up progress callbacks

Manual testing

1. Log in as crawler
2. Select "Create New..." > Upload
3. Fill form and submit. Verify form modal is minimized and dialog is displayed near toast stack
4. Wait for upload to progress. Verify file size is correctly displayed
5. Select "X" next to upload progress. Verify cancellation modal is displayed
6. Choose "Continue Upload". Verify cancellation modal is closed
7. Wait for upload to finish. Verify cancellation icon is replaced with link icon
8. Select link icon. Verify navigation to upload
9. Repeat steps 2-5
10. Choose "Cancel Upload". Verify upload stops and progress dialog closes after a few seconds
11. Go to "Archived Items"
12. Select "Upload WACZ"
13. Fill form and submit. Verify form modal is minimized and dialog is displayed near toast stack

Screenshots

In progress

Minimized in progress

Multiple in progress

Complete

Canceled

[emma-sg]

Found one small issue & left a suggestion

[emma-sg]

Saw one instance of the icon changing when closing the dialog, but I don't think that's a blocker here, looks great otherwise!

[tw4l]

I tried a fair few weird behaviors to see if I could break it, but this feature worked and had a very friendly UX the whole time. Nice work!