[RedTree] add UserFeedbackCheckFailure for app_commands (#6397)

Co-authored-by: Jakub Kuczys <me@jacken.men>

redbot/core/app_commands/__init__.py

@@ -69,6 +69,9 @@ from discord.app_commands import (
 )
 
 from . import checks as checks
+from .errors import (
+    UserFeedbackCheckFailure as UserFeedbackCheckFailure,
+)
 
 __all__ = (
     "AllChannels",
@@ -131,4 +134,5 @@ __all__ = (
     "rename",
     "user_install",
     "checks",
+    "UserFeedbackCheckFailure",
 )

redbot/core/app_commands/errors.py

@@ -0,0 +1,10 @@
+"""Errors module for the app_commands package."""
+from discord import app_commands
+
+
+class UserFeedbackCheckFailure(app_commands.CheckFailure):
+    """A version of CheckFailure responding with a custom error message."""
+
+    def __init__(self, message=None, *args):
+        self.message = message
+        super().__init__(message, *args)