* Clickhouse migration: add ingest_counters table
* Configure ingest counters per MIX_ENV
* Emit telemetry for ingest events with rich metadata
* Allow building Request.t() with fake now() - for testing purposes
* Use clickhousex branch where session_id is assigned to each connection
* Add helper function for getting site id via cache
* Add Ecto schema for `ingest_counters` table
* Implement metrics buffer
* Implement buffering handler for `Plausible.Ingestion.Event` telemetry
* Implement periodic metrics aggregation
* Update counters docs
* Add toStartOfMinute() to ordering key
* Reset the sync connection state in `after` clause
* Flush counters on app termination
* Use separate Repo with async settings enabled at config level
* Switch to clickhouse_settings repo root config key
* Add AsyncInsertRepo module