Have a way to look at small stacks

Sometimes there're stacktraces with small samples, which are not possible to "drill down" in the UI.

Although for most use cases we want to look at the "bigger" ones, it's still useful to drill down the smaller ones, specially in the context of exploration.

Suggestions of UI approaches are welcome.

Start by reproducing the small-sample stack trace case shown in the issue and inspect the current profiling UI behavior when drilling down is unavailable. Determine a UI approach that permits exploring these smaller stacks; done means users can drill into them without preventing the existing focus on larger samples.

Written by the indexing model from the issue text.