[Lens] Add to new dashboard flow doesn't actually add the visualization

[flash1293]

Kibana version: master

Describe the bug: Adding a visualization to an new dashboard doesn't actually add the visualization

Steps to reproduce:

1. Enable embedded visualizations flag
2. Go to Visualize
3. Create new Lens vis
4. Save and add to new dashboard
5. Dashboard loads without a Lens panel

Expected behavior:
Panel should be added to new dashboard

cc @poffdeluxe

[elasticmachine]

Pinging @elastic/kibana-presentation (Team:Presentation)

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[flash1293]

As this proved to be brittle (probably because the code is hard to unit-test as it lives in lots of plugins), it's probably worth having extensive functional tests for this.

[ThomThomson]

Very quick on the draw @flash1293, thanks for opening this!

This is a known incompatibility with the Deangularize Dashboard code, which is caused by #85493. In short, when loading into a specific dashboard instead of the most recently loaded dashboard the new hash router fires, which removes the state. I am working on a fix which switches out the implementation details of the state transfer service #85688

As for testing, writing functional tests for all of the Time to Visualize functionality is a major goal for the Presentation Team in the 7.12 timeframe. Before the switch is flipped by default, we hope to have extensive functional tests for all aspects of the flow.

[flash1293]

Thanks @ThomThomson , I guess we can close this as a duplicate of #85493