feat: instance remove (#4345)

* feat(instance): add remove instance event with projections cleanup

* fix(instance): corrected used id to clean up projections

* fix merge

* fix: correct unit test projection names

* fix: current sequence of lists and query for ensuring keypair based projections

Co-authored-by: Livio Spring <livio.a@gmail.com>
Co-authored-by: Fabi <38692350+hifabienne@users.noreply.github.com>

internal/query/projection/domain_policy.go

@@ -88,6 +88,10 @@ func (p *domainPolicyProjection) reducers() []handler.AggregateReducer {
 					Event:  instance.DomainPolicyChangedEventType,
 					Reduce: p.reduceChanged,
 				},
+				{
+					Event:  instance.InstanceRemovedEventType,
+					Reduce: reduceInstanceRemovedHelper(DomainPolicyInstanceIDCol),
+				},
 			},
 		},
 	}