Upload Compound Docs

This epic will define the upload aspect of Compound docs.

We do not currently support drag and drop upload from desktop to webui. So the only solution we can start with is by having a zip of the compound ready to be uploaded on the server. 

Files must be pre-formatted and made into a .zip which is loaded into the instance. A script in the instance recognizes the file and creates the appropriate folderish structure.

This is the way the Presales team, and the VF team are handling compound documents on their environment.

As an MVP, we can follow this path, but as soon as we support drag and drop, we should think in advance of this method and support a configurator for compound documents.