SQLite affected row count and last_insert_rowid

[itowlson]

Fixes #3092.

WIP for now

This adds two functions to the SQLite connection resource:

• changes() - the number of rows affected by the last insert/delete/update
• last_insert_rowid() - the rowid of the last inserted row

The names are taken from the SQLite API, and I'm in favour of sticking with that standard rather than giving them names that might be more self-documenting (stop shuffling your feet at the back, changes).

WIPness: the new functions appear to work but:

• It needs tests Added to the existing SQLite test
• It needs trying with libSQL
• It needs a world update (for dev purposes I shoved it into the 3.0 world but that's not appropriate for shipping) Done - see separate comment below
• I want to try to remove the v2/v3 duplication Done (hopefully satisfactorily)

I'm putting it into PR now so that 1. the integration tests pick up any regressions and 2. if folks have other things they want to put in then we can consider rolling them into a single rev.

The new interface is backward compatible and I did consider doing one of those "since" things to make it a minor version rev, which would eliminate all the duplication, but I provisionally went for a new interface because we are trying to shift from the fermyon: namespace to a spin: namespace. Happy to receive feedback on this!

[itowlson]

I've tentatively created a spin:[email protected] package to contain this. The alternative to to retain fermyon:spin@3, bump it to 3.1 and use an @since. This is more parsimonious and better expresses the compatibility guarantees, but doesn't contribute to moving us off the fermyon namespace.

I've done this as a separate commit do we can easily change or revert it independently of the functional work. Howl at me if you have something different in mind!