Update navigation benchmarks to measure the Navigation Process performance monitor

I realized the navigation benchmarks should measure CPU time spent in `Performance.TIME_NAVIGATION_PROCESS`. This requires modifying the benchmarks infrastructure to support a new measurement type (we have one for `Performance.TIME_PROCESS` already). Otherwise, we're just measuring setup time for each benchmark (which is important too, but should not be the only measurement of navigation performance).

Maybe we can map it to PROCESS in those benchmarks somehow, so that we don't need yet another column on the benchmarks website. I doubt any benchmark will need to measure both `Performance.TIME_PROCESS` and `Performance.TIME_NAVIGATION_PROCESS` at the same time.

Start by reading the benchmark infrastructure that already measures Performance.TIME_PROCESS and trace how measurement types become columns on the benchmarks website. Define the corresponding handling for Performance.TIME_NAVIGATION_PROCESS, then verify that navigation benchmarks report navigation-process CPU time without requiring an unnecessary additional website column.

Written by the indexing model from the issue text.