Add progress bar for files

[alexgoryushkin]

When uploading large files, the service does not inform the user about the progress of the upload and in general that it is going correctly

[Tanq16]

thanks for the feature request! i'll work on this in the coming weeks

[Tanq16]

huh! actually .. the progress bar i added does nothing, it's because on server side im using a fully buffered upload; i reopened this lol .. adding a progress bar turned out to be more troublesome than i thought! it'll take a while before i get back to this, but will definitely look into it

[Tanq16]

i've tried multiple times .. it's a hit or a miss .. it matches all online resources on how progress bars should be implemented. best i was able to determine was that it depends how the browser buffers large files for upload in which case it doesn't report progress generically. i'll close the issue and see if people have any other complaints regarding it in general. but for now, ive done what i could to best implement it. thanks for opening the issue!

[Tanq16]

just an update here - all issues are actually attributed to browsers and reverse proxy configurations. other than that, the base app works well with progress bars displaying correctly