allow using raising err inside implementation (#126)

this allows writing `raise InterpreterError` inside a method table, one
can still return a `interp.Err`, but using `raise` would simplify things
sometimes because Python does not have syntax sugar for error types.

Author: Roger-luo

src/kirin/interp/base.py

@@ -204,7 +204,10 @@ def eval_stmt(
         "simply evaluate a statement"
         method = self.lookup_registry(frame, stmt)
         if method is not None:
-            return method(self, frame, stmt)
+            try:
+                return method(self, frame, stmt)
+            except InterpreterError as e:
+                return Err(e, self.state.frames)
 
         # NOTE: not using f-string here because 3.10 and 3.11 have
         #  parser bug that doesn't allow f-string in raise statement