Improvements to checker

[kaleidawave]

• Adds support for classes (some of it ATM)
• Adds expected_value (not hooked up to anything yet)
• Adds function behavior and function scopes (improves the handling of this)
• Property keys are no longer always TypeId. New Cow<str> | TypeId produces less types, improves property handling and overall less overhead (🏇)
• Object.getPrototypeOf and Object.setPrototypeOf
• in and delete property additions
• Array.prototype.pop()
• Improved structure of calling (not fully)

Overall takes passing specification tests from 85 to 105!!!!

[github-actions[bot]]

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