Remove unused view methods to override social auth keys
Add submitter as a user on to SubmittedThing objects

- Update the api_v2 models
- Remove the submitter_name field from v1 models (replace it with a property that looks into the data)
- Migrate the data from submitter_name fields into the data blob
- Update the view querysets to prefetch submitter information
Copy data when rendering with GeoJSON renderer so as to not affect the original copy
Add ability to attach the current user to the posted submitted thing