Save original file name when uploading resume

[gsidebo]

In the resume upload UI, we show users the file name of the resume file they have uploaded. We don't save the original file name, so on the front end we have to do some string manipulation on the full file path in order to get that original file name. This is prone to silent failure – if, for example, we changed the destination path of uploaded files, and that path included an underscore, the file names would include a lot of confusing and user-irrelevant characters. We should save the original file names when a file is uploaded