Deprecate ServiceInsight

[lobkovilya]

Description

ServiceInsight is obsolete when using MeshServices. However, we still can't remove it as it's the only way GUI can get aggregated information in delegated gateway.

Also, GlobalInsight is using ServiceInsight:

kuma/pkg/insights/globalinsight/global_insight_service.go

Lines 119 to 146 in fc66bbf

	func (gis *defaultGlobalInsightService) aggregateServices(
	ctx context.Context,
	globalInsight *api_types.GlobalInsight,
	) error {
	serviceInsights := &mesh.ServiceInsightResourceList{}
	if err := gis.resourceStore.List(ctx, serviceInsights); err != nil {
	return err
	}
	for _, serviceInsight := range serviceInsights.GetItems() {
	services := serviceInsight.GetSpec().(*mesh_proto.ServiceInsight).GetServices()
	for _, service := range services {
	switch service.GetServiceType() {
	case mesh_proto.ServiceInsight_Service_internal:
	updateServiceStatus(service.GetStatus(), &globalInsight.Services.Internal)
	case mesh_proto.ServiceInsight_Service_external:
	globalInsight.Services.External.Total += 1
	case mesh_proto.ServiceInsight_Service_gateway_builtin:
	updateServiceStatus(service.GetStatus(), &globalInsight.Services.GatewayBuiltin)
	case mesh_proto.ServiceInsight_Service_gateway_delegated:
	updateServiceStatus(service.GetStatus(), &globalInsight.Services.GatewayDelegated)
	}
	}
	}
	return nil
	}