- Reformat styles

- Reformat styles

- Reformat styles

For all other input assistance presets, the status of the backspace key
is fixed.

Replace resize event listener with ResizeObserver to also detect size
changes of the surrounding grid

- Replace UpdateTextareaPipe with DynamicRowsDirective

The dynamic height of the textarea is calculated based on the available
width. However, accessing the width of the textarea often results in an
error.
For this reason, the calculation is now done using resize and change
events in conjunction with a timeout to wait for the textarea to render.

Media elements needs time to load and change the dimensions of the page

#441

- Use scss extension fpr styles file

Replace the assignment of the ElementComponent with the assignment of
a ElementComponent that will work in future versions of Angular

- Send metadata as voeReadyNotification to host

Displaying a message is task of the host
#398

- There is a page navigation only for not always visible pages
- Fix initialization of the button's action parameter

- Prepare usage in editor
- Remove test from ScrollPagePipe, because the call to "new Page" expected
  the initialization of GeometryComponent

- Remove css margins of floating keypad

- A floating keypad is generated inside a div with the class
  'cdk-overlay-pane'. Now the position of this div is updated when
  dragging the keypad.

- Add spans with 'nbsp;' to images to be able to align drop lists of
  cloze elements with images to the baseline.