Consider using sqlite-generate to make randomized test databases

[obi1kenobi]

https://github.com/simonw/sqlite-generate is a tool that has the ability to randomly generate SQLite databases full of random data: various data types, various shapes and sizes, foreign keys between tables, etc. See the README for some great examples, as well as discussion on foreign keys here: simonw/sqlite-generate#7

This tool was built to improve the test suite for Datasette, a popular data exploration and data set publishing tool by the same author. Datasette has some similar testing objectives as GraphQL compiler ("works with arbitrary datasets" etc.) and it would be a good idea to look into its testing approach in more depth and see if there are any aspects we should adopt. I'll open a separate issue for this.