[Flexible-schema] Refactor gql query runner to emit api event before processing to gql types

[Weiko]

Fixes https://github.com/twentyhq/twenty/issues/8300

Context

API events were created too late and were already formatted as Gql responses (including nesting with edges/node/type + formatting that should not exist in an event payload). This PR moves the emit logic to the resolver where we actually do the DB query