[feature] Allow overriding maxNodes on the flamegraph pages

[bobrik]

Currently maxNodes is a global setting.

Most of our users are happy with the default 16k. It also feels snappy even for large flamegraphs.

Others would like to have more fidelity for specific stacks, so they would like to increase the number to something like 64k. Unfortunately, 64k feels a lot less snappy, so we can't just set it as the default.

Currently one can change the number in the URL, but this is far from being convenient. It would be nice to allow adjusting fidelity on the flamegraph and comparison pages without affecting global settings.

[joey-grafana]

Hey you should be able to update the Maximum number of nodes in Profiles Drilldown settings. That will update from the default to something that suits your stack.

[bobrik]

Yes, I'm aware of this and I tried to describe why that doesn't work.