More robust storage of resumes

[Struck713]

Instead of passing a Base64 string around, create an Express route where we can upload (and later request for viewing) resumes https://github.com/hacksu/khe-revengeance/blob/e0d461e97f05fb84e60167d09573725e68e29b18/server/rpc-definitions.ts#L355-L372

[toBeOfUse]

This is noble. The base64 string method was the easiest way to set up uploads quickly because I could pass the string to a remult "backend method" instead of setting up an actual Express route/endpoint, but it's non-standard and inefficient