Add `rid` (request id) to logs

[grahamalama]

To make it easier to quickly find all log lines related to a request, we might consider adding a "request id" in our logs. This is specified as an optional MozLog field:

rid | string | unique request id for correlating other log lines | optional

This would help us, for example, quickly find all of the operations that were performed for one webhook request.

[bsieber-mozilla]

I like the idea of adding this! Being able to filter the logs more easily would be helpful.

What type of string/id? UUID? Any randomly unique enough value?

[leplatrem]

We could configure Nginx to set a X-Request-Id header on the request, and read it from FastApi (or using starlette-context)

There is apparently something available natively:
https://nginx.org/en/docs/http/ngx_http_core_module.html#var_request_id