- add unit-definition-menu module
- add verona module and move verona services and verona interfaces to it
  to make them available in different modules
- move the distinction of different page types to app component to make
  them available for unitDefinitionMenu component

Console logging is disabled in production mode by overriding the
function in `main.ts`

`PlayerStateComponent` encapsulates information about the status of the
player.

* Add verona interfaces to ensure type-safe communication with host
* To use the verona interfaces refactor the verona services

* 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.