AskToChooseOneService will ask users to select one service of the application if more than one exidi.

DoesCRDExist check CRD exist.

DoesNamespaceExist check namespace exist.

GetComponent get OAM component.

NewNamespace create namespace.

NewRestConfigGetter create config for helm client.

OAMLabel defines the label of namespace automatically created by kubevela.

IOStreams provides the standard names for iostreams.