Add more GC tracks in visualization

[xoofx]

Currently, the memory track is relatively limited because hardcoded with FireFox profiler. It only shows the total memory on managed allocations, but doesn't show the breakdown (gen1/gen2/gen3) and GC details.

Need to find a way to display these nicely. Could be done with separate marker track, but marker tracks are bound to a thread, which is not really our case here. I Could create a fake track, but not entirely sure it would work out of the box.