2-step file upload

[DAC098]

the file upload process has been a big of an issue it "feels" like. the upload
process will change to have a post request be made first to create the file and
then there will be a put request to actually send the contents of the file. the
system will just create an empty file and placeholder data and just return the
uids needed to actually upload a file.

this will help to cleanup the logic for the file upload process by splitting the
create and update processes apart vs how the currently are. will also help to
streamline the creation logic by using the post body to specify data vs having
to use http headers to get data.