[Technical] Refactoring of App, Breadcrumps and Nodes

[juli-txt]

Technical

• Breadcrumps should display the name of Topic and Course instead of "course" and "topic"
• Logic of App should be outsorced to a hook
• Title of node groups should be centered
• Default components should log on action via log.info
• BasicNode should be renamed to DefaultNode similar to DefaultGroup
• DefaultGroup has an unnecessary comment that should be deleted

Problem description

• Some refactoring is needed

Possible approch

• No approach needed

Acceptance criteria

• [ ] Created hook for App
• [ ] Refactored Breadcrumps
• [ ] Refactored nodes
• [ ] Added log.info to default components

Definition of Done

• [ ] All acceptance criteria are met
• [ ] The implementation of the User Story has been successfully accepted by the Product Owner
• [ ] The implementation is in GitHub
• [ ] A code review has been performed (or created in pairing program)
• [ ] Code conventions are followed
• [ ] Unit test coverage must be greater than 90%
• [ ] All tests must have passed
• [ ] Technical documentation created (Feature documented in GitHub Wiki)
• [ ] UML class diagrams and component diagrams created and up-to-date
• [ ] Documentation in realization created (source code)
• [ ] Changelog created (Clear description in merge request)
• [ ] There are no known bugs
• [ ] Rendering behaviour is optimized