2636: Chalk update and refactoring r=flodiebold a=flodiebold
This updates the Chalk integration to https://github.com/rust-lang/chalk/pull/311, which will presumably get merged soon, and refactors it some more, most notably introducing our own `TypeFamily` instead of reusing `ChalkIr`. It's still mostly the same as `ChalkIr` though, except for using Salsa `InternId`s directly.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>