Migrate redis_hll_counters.ide_edit.g_edit_by_sfe_monthly to Snowplow

Problem

The usage_activity_by_stage_monthly.create.action_monthly_active_users_sfe_edit metric is important to understand on a namespace level for Customer Service / Product Analytics.

Desired Outcome

The metric is available in Snowplow and includes the new context.

Implementation Hints

There are two places, where g_edit_by_sfe_monthly, is currently emitted:

1. In EditorUniqueCounter, a function that is actually never used, but which would forward the correct snowplow event already
2. In the blob_controller, through track_redis_hll_event. Since track_redis_hll_event is deprecated, we should replace it with track_custom_event from the ProductAnalyticsTracking module. To forward the event to Snowplow as well we have to include it in the Whitelist https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/controllers/concerns/product_analytics_tracking.rb#L70