Debug groups makes it easier to view from where an error comes from.
The backend can also implement its own callback to make it easier to
follow the API call structure in frame debuggers.
Now the callbacks are setup for each debug context.
The formating has been reworked to be less verbose and make errors
and warnings stand out from the notifications.
Errors are most of the time sufficiently explicit in their message.
This also remove the support for AMD_debug_output which is 10 years old.
This is related to the Vulkan port T68990.
