filter flame graph stacks #72

I'd really like filtering out some stacks in the GUI.. (probably it's possible in the perf cli somehow though I'm kinda newish to perf ).

Example usage:

Did whole system perf record, found out process node_exporter does its periodic work for 30s. Ok, I'm interested what the rest of the system is doing, so I could filter out matching regex (( e.g. if this stack or its parent stack match the regex ignore/include them ))