Allow users to upload directories as a resource to the OFRAK server

[dannyp303]

What is the use case for the feature?
#370 allows ofrak to create resources from a regular directory, and should be reflected in the GUI.

Does the feature contain any proprietary information about another company's intellectual property?
No

How would you implement this feature?
In the front end, walk the provided directory, and send each directory, file, and its data to the server. The server should write those to a temp dir and use that to create the resource.

Are there any (reasonable) alternative approaches?
Probably

Are you interested in implementing it yourself?
Sure, would like input from @rbs-jacob on uploading multiple files, as per a prior discussion regarding OFRAK Projects.