[Files] Size converter tool useful in Canvas Files page

[cpgalt]

I often need to free up space in my Files page (within its folder structure), and I find myself downloading a large image file, reducing its size using my Windows app, and then re-uploading the file again. If I'm working with many file, this becomes tedious. Of course, i can be more careful to use smaller files at the initial upload stage. But it would be useful to have a file size converter tool built into Canvas that could be used to modify file size for image files.