DiagnosticListener summary message is obscur and misleading

### Affected version

4.0.0-beta-4

### Bug description

Current messages always logs:

- an aggregate
- code instead of pseudo english messages to be understandable
- is always logged whereas messages are already logged so if people care they have what they need, aggregate can be a fun way to encourage people to fix it but actually just having the log is sufficient in 99% of the case and it avoids the duplication

goal here is to

- make configurabe the output
- try to display more meaningful messages