[Feature Request] Support for sqlite3_interrupt

Hey sql.js maintainers! Thanks so much for this great software, we've been getting great milage out of it!

It sounds like it's possible to add sqlite3_interrupt support based on your discussion in #461, it just hasn't been prioritized. We've implemented the suggested workaround of killing and re-instantiating the worker, but obviously it would be a lot more performant if we surgically interrupted queries.

Is this feature on your radar? Any idea of how much work it would involve? Thanks in advance!

Read the discussion in #461 and inspect how sql.js currently runs queries in its worker, including the workaround of killing and recreating that worker. Define how sqlite3_interrupt should be exposed and verify that an in-progress query can be interrupted without restarting the worker.