Refactor: Make file handling its own object/class, separate from scope #478
Description
[file_handler.js/file_existance.js to handle saving, downloading, and uploading of files.]
May need some exploration to see how possible this is. I'd suggest a class so that things like scope don't have to be constantly passed to functions in there.
Lets see if we can avoid using scope and page functions inside the file manager so that its functions don't all have to be async. That would mean avoiding needing data from the page if possible. Pass the data in after it's already been fetched.
This may not be possible. I'm thinking specifically of the download management aspect of this. Maybe uploading as well, depending on what's going on there.
[Note: [file names and key names, etc], or at least part of constructing names, might not be part of this because we need names for other things, like creating projects.]