Add error bars to histograms

[edugfilho]

Moved from mozilla/bigquery-etl#954

mozilla/bigquery-etl#954 (comment)

The computation for error bars are as described here in case 1: https://docs.google.com/document/d/1ipy1oFIKDvHr3R6Ku0goRjS11R1ZH1z2gygOGkSdqUg/edit#heading=h.8gnzmf4a2hjh

[edugfilho]

Notes from a GLAM triage discussion on Jan 9 2024 on this:

It would probably be useful to take a number of probes with different sample sizes and run this on them to see how big the error bars would get. It's hard to gauge how much we want to prioritize this. We decided to move this to the GLAM repo so we can keep a link to the conversation.