Adds the missing endpoints for documents, envelopes and
templates supporting file uploads in a singular request.
Also updates frontend components that would use the prior
hidden endpoints.
Adds support for multipart/form-data requests in the public api
allowing documents to be uploaded without having to perform a secondary
request.
Need to rollout further endpoints for envelopes and templates.
Need to change how we store files to not use `putFileServerSide`
