Show error message on evaluate also for hover context (#2006)

If a client sends an evaluate command with context=hover and if the
expression fails, the client received an error with the message
"Exception occurred during evaluation"

This wasn't very helpful. This changes the logic to treat `hover` just
like `watch` in the error case to send back `eval_result.result`. That
contains the message of the exception which is typically more useful.

Author: mfussenegger

src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py

@@ -1214,11 +1214,8 @@ def __create_frame():
             eval_result = pydevd_vars.evaluate_expression(py_db, frame, expression, is_exec=False)
             is_error = isinstance_checked(eval_result, ExceptionOnEvaluate)
             if is_error:
-                if context == "hover":  # In a hover it doesn't make sense to do an exec.
-                    _evaluate_response(py_db, request, result="", error_message="Exception occurred during evaluation.")
-                    return
-                elif context == "watch":
-                    # If it's a watch, don't show it as an exception object, rather, format
+                if context in ["watch", "hover"]:
+                    # If it's hover or watch, don't show it as an exception object, rather, format
                     # it and show it as a string (with success=False).
                     msg = "%s: %s" % (
                         eval_result.result.__class__.__name__,