[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