Use testcontainers to run backends for tests

[farodin91]

This transition to testcontainers allows to speed test runs because each class can have an own instance of the selected backend. This allows to run multiple test classes at same time.

Transition can be done step by step because each class need to edit to use testcontainers instead of the current methods to start the backend.

• https://github.com/testcontainers/testcontainers-java
• https://www.testcontainers.org/usage/generic_containers.html