Stack trace vanishes after navigating to certain views

Fix JMC-6923  helps to retain expanded/collapsed states of stack trace, when the user switches to other opened JFRs in JMC.

But if the user moves to other views (like JOverflow Instances/Treemap/Command/Progress etc) and comes back to stack trace view, then the entire stack trace gets vanished and a re-selection is required to get the stack trace back.

It will be a good idea to retain stack trace sessions even after switching to other unrelated views like JOverflow.