#499

- Background color must not be transparent for the stickied panel to 
overlay properly.

- Use TextImagePanel where possible

Toolbar is a single word, therefore any capitalized letters are errors. 
No need to sanitize, since this was broken anyway.

#384

#386

#453

Material update fix

causes problems after update

#452

... to create a new reference for options property.

Measure holds the value and a unit for CSS properties.

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

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.