Add data warehouse export connectors (Snowflake, BigQuery)

Sentry supports data forwarding to Segment, Amazon SQS, and Splunk, but has no native connector to data warehouses such as Snowflake or BigQuery. Enterprise customers with internal data lakes want to join Sentry error data with proprietary event streams (e.g., gameplay telemetry) without paying for duplicate storage.

- Existing forwarders: Segment, Amazon SQS, Splunk (error events only; no spans/logs)
- No first-class Snowflake, BigQuery, or generic data lake export
- SQS is the closest DIY path but requires significant customer-side infrastructure

Add first-class data warehouse export connectors (Snowflake and/or BigQuery as initial targets) with full event type coverage including errors, spans, and logs.

Reported by a gaming console customer (Triiodide Technologies).

Action taken on behalf of Richard Propst.

Start by examining the existing Segment, Amazon SQS, and Splunk forwarders and how they handle error events. Scope the Snowflake and BigQuery connector requirements, including spans and logs; done means first-class export support covers errors, spans, and logs for the selected targets.

Written by the indexing model from the issue text.