fix: allow using type aliases in struct patterns and constructors

[TomAFrench]

Description

Problem*

Resolves

Summary*

This PR adds behaviour to the elaborator such that when looking up a type fails, before throwing an error we instead look up a type alias using the same path. Should this resolve to a type alias, we then return the type to which this is an alias, otherwise we return the original error.

This allows us to use type aliases interchangeably with the associated type in struct patterns/constructors.

Additional Context

Documentation*

Check one:

• [x] No documentation needed.
• [ ] Documentation included in this PR.
• [ ] [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• [x] I have tested the changes locally.
• [x] I have formatted the changes with Prettier and/or cargo fmt on default settings.

[TomAFrench]

Looks like this PR causes panics if a type alias is used in a return type position.