🔧 [Refactor] Fix workflows

Created by: ulfgebhardt

🔧 Refactor ticket

@mahula Please fix the workflows:

Todo

• devide test workflow into test-backend.yml, test-e2e.yml, and test-webapp.yml
• unit test coverage checks:
  • configure jest for coverage check
  • remove coverage check jobs from backend and webapp workflows
• add file filters (backend, docker, and webapp)
• use the file change check job in workflows
• resolve docker build dependencies for unit test jobs
• speed up end-to-end testing workflow