✨ feat: upgrade to testcontainers v2

[gaeljw]

Aims to fix #516

As per the v2 CHANGELOG:

• dropped dynalite support
• renamed KafkaContainer to ConfluentKafkaContainer
• added KafkaContainer that targets the Apache Kafka image (as testcontainers-java does) ( ⚠️ this might be considered a breaking change)
• bump Kafka Confluent container default version to 8.1.0
• bump Kafka libraries used in Kafka module test to be aligned
• removed references to JUnit 4
  • especially, it was still used in Scalatest/Specs2 only to build a test description that in the end happened to only be the class name
  • removed already deprecated methods referecing JUnit 4 Description
• modules: as a couple of default image names are now private, had to copy them in the Scala class (I've seen that it was already done in some other modules)
• modules: removed proxy methods/attributes for methods/attributes not existing anymore upstream
• build: use v2 modules and adapt imports
• build: remove JUnit 4 dependency

[gaeljw]

@gaeljw try without it, maybe the CI doesn't need this? In local on my laptop it raises errors due to potential conflicts scala-xml 1.x and 2.x

[gaeljw]

Ok, tests are succesfully locally now. You can approve to run on the CI :)

[dimafeng]

@gaeljw Thank you so much! I'll try to review it this week