chore(ssa refactor): Handle function parameters

[jfecher]

Related issue(s)

Resolves #

Description

Summary of changes

• ssa ir/builder:
  • Adds functionality to add block and function parameters in FunctionBuilder, DataFlowGraph
  • Adds missing Return block terminator to end a function
  • Adds Reference and Function types
• ssa-gen:
  • Adds correct parameter handling with tuple flattening to FunctionContext, ssa-gen pass
  • Restructures Value into Tree<Value> so that we can have helper functions like map_type to map Tree<T> to Tree<U>. This is often useful for mapping types Tree<Type> to values Tree<Value> or vice-versa.

Dependency additions / changes

Test additions / changes

Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt with default settings.
• I have linked this PR to the issue(s) that it resolves.
• I have reviewed the changes on GitHub, line by line.
• I have ensured all changes are covered in the description.

Documentation needs

• This PR requires documentation updates when merged.