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

* Fix bug for small pages
* Add functionality for tabbed pages
* Use layoutContainer as container for intersection detection
* Rename properties and methods

Teststudio does not show patch versions.

Move `MatDialogModule` from editor to common
Add `AlertDialog` to player

Check whether `unitDefinition` or `unitStateDataType` are undefined is
done within the verify methods

* 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`

When elements are dynamically positioned there is no space below the elements

* Use `IntersectionObserver` to detect page position while scrolling

* Pages can be scrolled or tabbed
* Labels of pages can be shown and hidden
* Always visible pages can be left, right, top or bottom
* Layout of pages is now handled in `LayoutComponent` and removed from
`PlayerStateComponent`
* Due to the `ScrollIndexDirective`, pages with scrollbars have similar
interfaces as pages with tabs

Merge the `unitDefinition` with the `unitState.dataParts` to insert the
saved values

Required to decide whether the `section` or `element` should be inserted
or appended to its `formArray`

Required after changes in element components
(commit: 9e3c0613)

* Remove workaround with `Promise.resolve().then(() => ...`
* Use `changeDetectorRef.detectChanges()` after updating the validators

Make the initialization consistent

Getter work like functions and are executed every time Angular change
detection runs.

* Since always visible pages are removed from the order, form
arrays must be rearranged
* Refactor getter as properties in `PlayerStateComponent`. Getter
work like functions and are executed every time Angular change
detection runs.

* Create `FormGroups` without ids
* Add `FormArray` for elements

* Add section array to the form groups of the pages
* Remove unnecessary component factory from `SectionComponent`

* Add specific translation file for editor in assets/i18n
* Add first translations for toolbar

Refactor some translations

more information about [ngx-translate](https://github.com/ngx-translate/core)