Idea: Filter left-heavy and sandwich views using selected window of time order view

[jherman3]

When recording profiles, the profile will often include some unrelated activity (e.g. one-time setup code, idle thread time if recording wall-time rather than cpu-time traces) that I want to ignore from my analysis. The time-order view is great for zooming in on the "interesting" section of execution, but the left-heavy and sandwich views will always consider the global profile state in computing stacks to collapse.

It would be useful if there was an optional filtering mode that ran the left-heavy or sandwich rendering on only some subset of the input trace - a natural way to fit this into the current UI would be to reuse the selected time-order window as this filter since it seems we already persist the zoomed area across each viewing mode.

[jherman3]

After looking more closely for duplicates I found #366 / #39 - will close in favor of those.

I think we could eliminate the need for "undo" if we treat the key as a toggle between cropped and uncropped mode rather than a one-time destructive operation.