Structured logging
### Proposal
All logs should be available in a structured format for easier parsing, specifically JSON format:
- [x] api_json.log
- [x] [application_json.log](https://gitlab.com/gitlab-org/gitlab/-/issues/22812)
- [x] audit_json.log
- [ ] database_load_balancing_json.log
- [x] exceptions_json.log
- [ ] gettext_json.log
- [ ] gitaly_json.log (gitaly-test_json.log)
- [ ] grpc_json.log
- [x] graphql_json.log
- [ ] importer_json.log
- [ ] migrations_json.log
- [ ] praefect_json.log (praefect-test_json.log)
- [ ] sidekiq_client_json.log
- [x] Rails logs
- [x] development_json.log
- [x] production_json.log
- [x] test_json.log
### Related issues
- [Standardize timestamp format in log files](https://gitlab.com/groups/gitlab-org/-/epics/2575)
- [Consider dropping unstructured rails logs](https://gitlab.com/gitlab-org/gitlab/-/issues/23070)
epic