move types from spec into separate package

cmd/main.go

pkg/cluster/cluster.go

pkg/cluster/filesystems.go

pkg/cluster/k8sres.go

pkg/cluster/pg.go

pkg/cluster/pod.go

pkg/cluster/resources.go

pkg/cluster/util.go

pkg/cluster/volumes.go

pkg/controller/controller.go

pkg/controller/pod.go

pkg/controller/postgresql.go

pkg/controller/util.go

pkg/types/namespacedname.go

pkg/types/types.go

pkg/types/types_test.go

pkg/util/config/config.go

pkg/util/users/users.go

pkg/util/util.go

pkg/util/util_test.go