Rendered DOM access service

[egil]

To enable test/mock services to intercept a rendered AngleSharp DOM before it is available to the user through the component under test, i.e. rendered component or rendered fragment, we need a service, that the test context in the web project passes a new rendered DOM each time it is generated and when it is replaced/disposed.

The service needs to provide the following functionality to other services:

• A way for them to invoke code on a rendered DOM when it is first generated
• A way for them to invoke code on a rendered DOM when it is disposed/replaced

That will allow something like the mock NavigationManager to add event listeners to e.g. document, and listen for on onclick events on anchors elements.

Related

• Used by Fake NavigationManager #117
• Depends on Events does not correctly bubble up the DOM tree #119