Create Type Inference engine for Morphir AST/Syntax

# Create Type Inference engine for Morphir AST/Syntax

Given a Morphir AST/Syntax we want to be able to decorate the tree with type inference information.
We can look at the Rust based Hindley Millner.

https://crates.io/crates/polytype

Start by reviewing the Morphir AST/Syntax representation and the Rust-based Hindley-Milner approach in polytype. Define how inferred types should be represented and attached to the tree. Done means a Morphir AST/Syntax can be traversed and decorated with type inference information.

Written by the indexing model from the issue text.