Add benchmarks for scikit-image functions introduced in 22.08

[grlee77]

This PR adds benchmarks for a few of the recently introduced functions.

It also uses more realistic nD label object generation for the segmentation benchmarks.

[grlee77]

no need to immediately review this for the 22.08 release since we don't ship the benchmark scripts

[gigony]

@gpucibot merge

[jakirkham]

@gpucibot merge