Progress isn't reported on multiple uploads correctly.

[ara4n]

Steps to reproduce

1. Hit the upload button
2. Select a set of files to upload
3. Discover that the progressbar only shows you one file at a time as it uploads, making it impossible to judge progress.

Outcome

What did you expect?

Show progress across the full set of files, so you know how long it'll take in total.

Operating system

No response

Application version

Element version: 1.12.8 Crypto version: Rust SDK 0.16.0 (95b5e83), Vodozemac 0.9.0

How did you install the app?

No response

Homeserver

No response

Will you send logs?

No