#470: Timeline refactoring

[benitsch]

• Introduce TS interfaces for Timeline.
• Do not save custom data on vue-cal Event object (only cId).
• Use mapper and EventDetail object for more detailed information on e.g. dialog.
• Avoid using class names in conditions for display information.

[github-actions[bot]]

Test Results

0 tests  ±0   0 :white_check_mark: ±0   0s :stopwatch: ±0s 0 suites ±0   0 :zzz: ±0  0 files   ±0   0 :x: ±0 

Results for commit c6228a07. ± Comparison against base commit bb10a63c.