Add ability to pass in job_settings to generate session.json and data_description.json

[rcpeene]

Is your feature request related to a problem? Please describe.
We'd like to have all the metadata generation taken care of during the upload process so each project doesn't have to manage the code for this. This minimizes the steps needed to be run manually during the upload process.

Describe the solution you'd like
The session.json and data_description.json have some required values that can not be automatically extracted from files. These must need to be passed in by the user. Having a job_settings input parameter, which would be a json containing the necessary values and perhaps some additional optional onces.

Describe alternatives you've considered
I'm not quite sure what alternative solutions are. What we currently do is have our own upload script which does this generation.

Additional context
The required values that can't be automatically determined (that I have identified) are the following:
project_name, license, platform, institution, funding_sources, investigators, modalities, related_data, project_description, iacuc_protocol, session_type