This prevents the browser from trying to translate the page on
German systems

This is done according to the Angular best practices and minimizes
namespace collisions when using other packages which might use the same
selectors.

Technically the selectors are not even becessary since we use an Angular
component factory to create element components but it is still useful
for the DOM element naming, for debugging purposes for example.

- Improve variable naming for unit definiton type. (version string)
- Use 'iqb-aspect-definition@1.0.0' as value which better communicates
  the purpose of the data.
- Also update the HTML files with the new definition. (Even though it is
  not checked anywhere.)

This reverts commit 93e62a4a.
Teststudio does not accept verona 4 specification data

see https://github.com/iqb-berlin/verona-data-specifications/blob/main/responses/manual_iqb-standard.md

The version used does not support the new json-ld format yet and errors
out.

Use verona-module-metadata.json to define json meta data in html header

The version is taken from the package.json file and replaced in the 
html.

Teststudio does not show patch versions.

* Define data version types data versions for `unitDefinition` and
`unitState` in meta tag of index.html
* Separate `MetaDataService` from `VeronaPostService`
* Extend `MetaDataService` to verify data versions of `unitDefinition` and
`unitState`

* Implement `VeronaSubscriptionService` to subscribe to messages from
the host of the player
* Implement `VeronaPostService` to post messages to the host of
the player
* Implement `NativeEventService` to subscribe to events like 'scroll',
'blur' and 'focus'
* Remove js code from wrapper index.html. It is no longer needed.

* The wrapper of the player component listens to the `valueChanged`
event and posts a message to the host of the aspect-player
* Improve code style and remove lint errors

Use `build-player-prod` to build a player version of the
aspect-player which can be used in test-center and test-bed.
The player needs exported unit definitions from the
aspect-editor.

Using scripts also used by the abi player. Aslo adding html wrapper 
files for dev and production. Those have only been modified minimally 
and need to be revised.