Make Metabase generate "events" to easily integrate with external applications

Is your feature request related to a problem? Please describe.
Currently the only way to integrate Metabase with external applications (a-la if-this-then-that) would be to either mirror the requests on the reverse-proxy through a sidecar pattern (see ticket 9588) or use triggers in the DB that call an external service.

These 2 types of integrations are architecturally disgusting, since we're discovering events on layers that shouldn't be used for that. These events should be published by the logic layer on the moment that the event is processed.

Events like:

• a user is created/authenticated/disabled, etc
• a user creates/updates/deletes a dashboard/question/metric/segment/collection, etc
• a sync started/errored, etc

Describe the solution you'd like
Any event that we currently generate internally in the application should be sent as an HTTP call to an external application

Describe alternatives you've considered
Described above

How important is this feature to you?
2nd time I hear about this from customers

Additional context
NA

The request identifies the application logic layer and HTTP calls to external applications as the relevant entry points, but names no files or tests. Start by mapping the internally generated events and their callers; done would require a defined, verified approach for publishing the supported events externally.