Google Analytics 4 does not send events without a mapping

[dobesv]

For some reason the Google Analytics 4 integration seems to require all events to have a mapping configured to translate events from the system to Google Analytics 4 events.

This is quite different from how it works with the old analytics. Is there any documentation for the idea behind this? Just trying to figure out how to transition to GA4 with analytics.js.

(cc @gpsamson)