assistant2: Restructure tools in preparation for adding more (#11213)

This PR does a slight restructuring of how tools are defined in the
`assistant2` crate to make it more amenable to adding more tools in the
near future.

Release Notes:

- N/A
e3de440715Marshall Bowers committed on 4/30/2024, 3:12:44 PM· committed by GitHubparentd743c19
3 files changedLine totals unavailable