Adds Validation for Union Type Variants.

[MelbourneDeveloper]

TLDR

This PR improves the handling of Result types in pattern matching, fixing issues with type inference and string conversion, and adds validation for union type variants.

What Was Added?

• Added more robust handling for Result types in convertValueToStringByType to handle raw values (arithmetic operations) that are masquerading as Result types.
• Introduces the isSpecialConstructor function to detect special built-in constructors like Success and Error, and validation for union types.

What Was Changed / Deleted?

• Modified convertResultToString to use locally defined sprintf and malloc to ensure usage of correct declarations.
• Enhanced generateSuccessBlock and generateErrorBlock to create new type inference environments for each match arm.
• Strengthened type inference for pattern variables within Result types in the error block, specifically extracting the error type from the Result generic type.
• Replaced passing test to failing test and updated validation

How Do The Automated Tests Prove It Works?

• Updated existing unit tests to validate exhaustiveness for match arms and added test for cases where an unknown variant is used in match.

Summarise Changes To The Spec Here

• Updated documentation to include Union Types