[wip] Refactoring backend node service to support saving email address

- Moved from sponsorship-form to drc-backend
- Moved code around to have sponsorship.js and coming-soon.js
- Added mongodb client currently hardcoded to localhost
- Added a .save method for coming-soon to save an email address
- Reworked all ansible files to accomdate directory change
- part of #669
This should probably be a variable that gets populated in the secrets.*.yml files. This way we can vary it by environment. Also there might be a password involved in that DSN, maybe.