Resolve "See reed comments (participant)"

Information

• edited components of comment-list and create-comment
• edited comment service
• participant can now see his own comments
• using same component as creator, but he should not be able to use same functions

Testing

• comment list should be different between participant and creator ( no button-action for participant, participant should only see read status )
• participant should only see his own comments
• creator should see all comments in room
• creator can delete comments and change read status
• participant should see instantly his new created comment

Closes #130 (closed)