Update all tests to use JUnit 5

Now that testcontains supports JUnit 5, we should be able to update all remaining JUnit 4 tests to 5. The only thing which might be in the way that there is currently no way of having class-level parameters. But that is on JUnit's roadmap

### Checklist

- [ ] apm-agent-core

apm-agent-plugins/

- [ ] apm-apache-httpclient/apm-apache-httpclient3-plugin
- [ ] apm-apache-httpclient/apm-apache-httpclient4-plugin
- [ ] apm-api-plugin
- [ ] apm-ecs-logging-plugin
- [ ] apm-es-restclient-plugin/apm-es-api-client-test
- [ ] apm-es-restclient-plugin/apm-es-restclient-plugin-5_6
- [ ] apm-es-restclient-plugin/apm-es-restclient-plugin-6_4
- [ ] apm-es-restclient-plugin/apm-es-restclient-plugin-7_x
- [ ] apm-finagle-httpclient-plugin
- [ ] apm-httpclient-core
- [ ] apm-java-concurrent-plugin
- [ ] apm-jaxrs-plugin
- [ ] apm-jaxrs-plugin-jakartaee-test
- [ ] apm-jdbc-plugin
- [ ] apm-jms-plugin/apm-jms-plugin-base
- [ ] apm-jms-plugin/apm-jms-spring-plugin
- [ ] apm-kafka-plugin/apm-kafka-base-plugin
- [ ] apm-kafka-plugin/apm-kafka-headers-plugin
- [ ] apm-kafka-plugin/apm-kafka-spring-plugin
- [ ] apm-logging-plugin/apm-log4j2-plugin
- [ ] apm-micrometer-plugin
- [ ] apm-mongodb/apm-mongodb3-plugin
- [ ] apm-mongodb/apm-mongodb4-plugin
- [ ] apm-mongodb/apm-mongodb-common
- [ ] apm-okhttp-test
- [ ] apm-opentelemetry/apm-opentelemetry-plugin
- [ ] apm-opentelemetry/apm-opentelemetry-test
- [ ] apm-rabbitmq/apm-rabbitmq-spring
- [ ] apm-redis-plugin/apm-lettuce-3-tests
- [ ] apm-redis-plugin/apm-lettuce-plugin
- [ ] apm-spring-resttemplate/apm-spring-resttemplate-plugin
- [ ] apm-spring-webmvc-plugin
- [ ] apm-urlconnection-plugin
- [ ] apm-vertx/apm-vertx-common

integration-tests/

- [ ] application-server-integration-tests
- [ ] spring-boot-1-5
- [ ] spring-boot-2/spring-boot-2-base