#243

The sanitizer is now a service, so it is testable.
Since it uses the IDService it needs to be a real service as well.

Both are used by the player therefore moved to common.

- Clearer methods with only one return value
- better naming
- comments

since the player uses it as well

- add unit-definition-menu module
- add verona module and move verona services and verona interfaces to it
  to make them available in different modules
- move the distinction of different page types to app component to make
  them available for unitDefinitionMenu component

The package karma-spec-reporter is to show more info about run tests on 
the console.

Numbers on the test files refers to the version (2 digits for minor; 
patch number ignored).

Just innerHTML does not work properly because the Material stylings do 
not take effect. Just using another element (div in this case) solves 
the issue.

New name: richTextOptions

Unit definition version has been raised accordingly.

Use own method `handleRadioButtonGroupElement`

This reverts commit d053d03c.

This feature will first be developed properly in a branch.

The height of an empty droplist can't be calculated on ios 14
because it's in a flex container

Most importantly dynamic sections are now default.

Cloze documents now use this correctly.

#233

#229