Use TypeCheck.jl to sort-check instances

[olynch]

We could use https://github.com/astrieanna/TypeCheck.jl to get static guarantees that instances of theories were at least sort-correct. Could be pretty useful.

[olynch]

Oh wait, that's 10 years old; I thought it was only 1 year old.

[olynch]

We could use https://github.com/julia-vscode/StaticLint.jl.

[olynch]

Or just code_typed.