[Lens] Show description in dashboard title

[timroes]

For classical visualizations the description when saving it will be shown as an information on the dashboard:

For Lens visualizations the saved description will not be shown here. This should behave the same as for visualizations.

Related: https://discuss.elastic.co/t/lens-description-not-displayed/238060

[elasticmachine]

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

[wylieconlon]

This can be done with a small amount of code, so I think it's a good candidate for fix-it-week.

[dej611]

Closed by #78767