We want to merge the JUnit 5 extension from the community hub (https://github.com/camunda-community-hub/camunda-bpm-junit5) into the platform monorepo (https://github.com/camunda/camunda-bpm-platform).

The following content from the JUnit 5 repository should be merged:

• README.md
• core

The content should be moved to test-utils/junit5-extension in the platform repo.
The git commit history should be preserved.
Make sure to adjust the pom.xml and other resources to tie the JUnit 5 extension into the platform maven structure.