new benchmarker/benchmarks; keeps old benchmarks

[tabcat]

adds/updates benchmarks and an npm script to use the new benchmarker. i decided not the do anything with the old benchmark files yet but we can add that as part of the pr if decided.

related: https://github.com/orbitdb/benchmark-runner/pull/32

[aphelionz]

We should probably remove the call to npm run benchmark in CI until we have a way to reliably compare performance across builds