Add a Histogram Metric

A histogram metric would be nice to visualize things like the distribution of allocation sizes. We would probably need to specify the bucket ranges when the `Histogram` is created. Logarithmic or linear-sized buckets over a range would work.

This would be useful for https://github.com/RelationalAI/raicode/issues/9073#issuecomment-1239427099.

cc @vilterp 