- Rewrite interface 'VopMetaData'
- Add parameter 'metadata' to VopReadyNotification

- A HotspotImage has an image and divs placed on it, which are used
as hotspots
- Inherits from FormElementComponent, which is why the hotspots are kept
  as a list in the value property.
- Can be validated as required and uses its own custom validator

- This makes the behavior identical to real form elements
- To trigger the focusout event, the HTML element needs
the tabindex attribute

Instead, use :host in conjunction with ::deep

- Use fixedSize always together with dynamicPositioning!
- Rename css class 'center-content' to 'fixed-size-element'
'fixed-size-element' ensures that the content does not overflow.

The previous solution, which uses a top position of 50%, did not work on
iPad

- This improves scroll snap behaviour
- Set background color of page
- Interpret the margin of a page as padding. What it really is