Show download progress bar in Filelist

### Is your feature request related to a problem? Please describe.
When i download Something i have no idea how long it will take.
thus, when i can leave the house/wifi, if i need to adjust the network im in etc...

### Describe the solution you'd like
Show a Progress bar for each file in the file list like so:


### Describe alternatives you've considered
If i start multiple Downloads (or a sync even) **additionally** there should be a presistent Android notification ON TOP (with filecount and progress bar, and eta)

### Additional context
https://github.com/nextcloud/android/issues/2414
Same or similair could be done for uploads