Add Snowplow thread count & timeout behind a FF

What does this MR do and why?

Add Snowplow thread count behind a FF

This is done in an effort to debug this bug: #562794

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Enable the feature flags
2. Make sure that Snowplow is still working, by triggering events locally and checking them with snowplow-micro

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