Fix front-end tests + refactoring

General:

• remove unused test system docker-compose
• update package.json with new test packages and updated react-tooltip
• include new test packages in setupTests.js
• update gitlab ci/cd pipeline
• update readme

Test fixing:

• update mocked template schemas with production versions
• remove outdated test data mock + functionality to retrieve it
• remove test console errors for react v17-v18 with mock spy in testHelper.js
• create generic test helper functions
• refactor create.test for Scheduling
• fix found bugs in create for Scheduling via (unit tested) create.helper
• format create for Scheduling