- Split text field and drop list, so they can have differing props
- Improve their dimension default values
- Improve alignment of all cloze children components
- Add dynamic width parameter of toggle buttons to dimension properties
panel. Therefore the postion tab can always be shown and no longer needs
a condition.

The span element created by using rich text via innerHTML makes the 
click listener not trigger. Making the innerHTML 'click through' solves 
the issue.

#244

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.

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

Cloze documents now use this correctly.

#229

- Use `inputmode` 'none' to hide the virtual keyboard of the os
- Use DeviceService to detect if the player is running
on a mobile device

verticalButtonAlignment is the new property for likert rows, which tells 
the actual radio button to either be at the top or in the middle.

Also rename LikertColumn to ColumnHeader, since it is not exclusively 
used by likert.

- A new new editor component has been created for this, which has a
reduced interface and produces span-elements instead of paragraphs.
- Since the created HTML (span with CSS) is regarded as potentially
harmful it needs to be sanitized. For element components the sanitizer
is put in the abstract parent element-component-directive.

This allows showing the contained text in multiple columns.

There were several issues with it's properties, which could not be 
changed.
Now it is properly initialized and prop change get actually handled.

Rename KeyboardComponent to KeypadComponent
Rename KeyboardService to KeypadService
Split LayoutComponent into LayoutPlayerComponent and
LayoutPagesComponent
Prepare the introduction of an additional keyboard

Replace custom pointer events with native pointer events

Instead, use Textfied component with the property isClozeChild

Remove duplicate code

Disable spelling correction as well
- Use the attributes autocapitalize, autocorrect, spellcheck
- Replace [value]="elementModel.value" with
value="{{elementModel.value}}" to prevent lint errors

belongs to commit #14dcebca