Return list of applications in the `Namespace`.

ApplicationConfiguration is the part of the manifest describing the configuration of the application

AppDeployment contains all the information specific to an active application, i.e. one with a deployment in the cluster.

AppRef references an App by name and namespace

ApplicationOrigin is the part of the manifest describing the origin of the application (sources). At most one of the fields may be specified / not empty.

ApplicationStage is the part of the manifest holding information relevant to staging the application's sources.