Download progress popup should show current-out-of-total size, rather than (only) count

[SaphireLattice]

If there's no data for this, servers should be modified to actually report the size of files. If there is, well, yeah.

But it feels annoying that the download progress is just this opaque number that either feels like it's going fast then suddenly hits a bigger file and slows down, or the big files get downloaded first and you dread the "10/2000" readout.

[PJB3005]

The problem is that total download size isn't actually known due to compression. The CDN would have to buffer a 150+MB download response to get the total byte size.

[SaphireLattice]

Honestly even uncompressed size would be rather useful? Sure it won't be accurate, but it will be at least somewhat more representative than the file count