Set events.target_type to project for new push events

See 'target_type' parameter for Events API is nil f... (&19098 - closed) for context

Currently, project events are created without a set target_type and target_id. This is causing a problem with our Events RESP API as the target_type filter always gives an empty result for project.

We need to ensure that new events created for projects gets an appropriate target_type.

Implementation Guide

See !203965 (closed) as starting point