Show current upload speed

This was once a feature but was lost when migrating from jQuery to Vue.

Original request: https://github.com/nextcloud/server/issues/37411

![Image](https://github.com/user-attachments/assets/f43db0f2-6546-4c0f-b748-31c5f317fbb0)