feat: add high level language feature to mini-calc

[vanilla-extracts]

Add high-level language feature and a compiler

• Type declaration
  • Sum type
  • Record type
• Pattern matching
  • deconstruct sum
  • deconstruct record

Depends on #54 and #63

[leana8959]

Regarding sum types: we could implement something like the Haskell notation

data A = Foo Int | Bar Int

And we treat the constructors as functions. What do you think about this syntax in the rest of the calc language? Or maybe we could stick to using lowercase, I don't think that makes a huge difference.

What notation do we currently have in calc in terms of defining datatypes? : A ? Do we allow user to type their values?

Also, if we were to implement pattern matching, I think it would be nice to start with match similar to Rust.
I don't know if we should allow patterns in a = b variable bindings. The problem with sum types is that these matches can be refutable and we need to decide what that means (crashing the computation? raising an error gently?)

Regarding record types (aka labeled product types), we could envisage how it looks like in parallel so the syntax and semantic is coherent.

Remember to drink water 🫡