[Lens] Should store unsaved visualization in session storage and prompt to restore when getting back

[shahzad31]

Describe the feature:

When you are working in lens, often times you only want to explore data and don't want to create new saved object visualisation. In that case if you are working on something and you move to some other kibana app, lens clears the state of the chart.

I propose that in that case, it should prompt the user to restore the previous state similar to how dashboard app is handling it. User should be able to restore the progress by browser back button.

[elasticmachine]

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

[flash1293]

@ghudgins We could do something similar to dashboard with an "unsaved draft". It won't give us full undo/redo, but it would probably solve the most pressing needs.

[stratoula]

In 8.7 lens is going to allow the users to Share a visualizations without saving. This creates a url that has stored the current state and can be used later to restore this state.

[stratoula]

I am closing this as the new share functionality in Lens can help to keep your state in a url without saving the visualization