typecheck: reject unknown class field types

tests/test_validate_ci_workflow.py

@@ -26,6 +26,8 @@ class ValidateCiWorkflowTests(unittest.TestCase):
             run: python3 tools/validate_version_convention.py
           - name: Packages
             run: python3 tools/validate_package_security.py
+          - name: Compiler warnings
+            run: python3 tools/validate_compiler_warnings.py
           - name: CI workflow
             run: python3 tools/validate_ci_workflow.py
         """

tests/typecheck_unknown_field_type_bad.claro

@@ -0,0 +1,5 @@
+CLASS Player
+    HAS score BANANA
+END
+
+NEW Player player