* Update Sites.Cache
So it's now capable of refreshing most recent sites.
Refreshing a single site is no longer wanted.
* Introduce Warmer.RecentlyUpdated
This is Sites Cache warmer that runs only for
most recently updated sites every 30s.
* Validate Request creation early
* Rename RateLimiter to GateKeeper and introduce detailed policies
* Update events API tests - a provisioned site is now required
* Update events ingestion tests
* Make limits visible in CRM Sites index
* Hard-deprecate DOMAIN_BLACKLIST
* Remove unnecessary clause
* Fix typo
* Explicitly delegate Warmer.All
* GateKeeper.allwoance => GateKeeper.check
* Instrument Sites.Cache measurments
* Update send_pageview task to output response headers
* Instrument ingestion pipeline
* Credo
* Make event telemetry test a sync case
* Simplify Request.uri/hostname handling
* Use embedded schema, apply action and rely on get_field
This commit adds an option to override `http://localhost:8000` in
`mix send_event`. This is useful when running the server in another port
or with remote servers such as staging.