Upload file to Dropbox

Build tooling to upload a file (`.db`) to Dropbox without Dropbox installed or signed in.

Links:

- [Generate a token](https://dropbox.tech/developers/generate-an-access-token-for-your-own-account)
- [Dropbox guidance for Python](https://www.dropbox.com/developers/documentation/python#overview), with an [app to upload a folder](https://github.com/dropbox/dropbox-sdk-python/blob/master/example/updown.py).

Start with the linked Dropbox Python documentation and the example at example/updown.py, then review the linked instructions for generating an access token. Done means the project can upload a .db file to Dropbox without Dropbox installed or the user being signed in.

Written by the indexing model from the issue text.