feat(timeseries): Add cross trace querying

[wmak]

• This adds support for the cross trace queries to the timeseries endpoint

[aliu39]

I'm curious how exactly the TraceItemFilters are applied to filter another item type? Is it via trace_id? E.g. if I do
"query all spans where log.severity = warn"
It first gets all traces where log.severity = warn, then filters spans based on that?

[wmak]

@aliu39 yes you can read more here; https://github.com/getsentry/snuba/blob/master/snuba/web/rpc/v1/resolvers/common/cross_item_queries.py#L67

I'd call this parameter experimental and not prod ready right now though so please don't use it yet

[aliu39]

@wmak got it thank you!