Story #1150: As a user, I can lazily fetch repositories
pulp-admin needs to have support and helptext for configuring --lazy=active and --lazy=passive for repos
Once the server and its plugins are ready and configured to support lazy loading using the active/passive sync, the CLI needs to expose these options to the user so the user can configure a repo to sync lazily in a specific way. This is done using additional importer configs as described in task #1200. These need to be able to be set from the CLI and need to have corresponding helptext. If --lazy is not specified no additional config value for the importer will be set and the normal non-lazy sync will take place as it always has.
The CLI has a notion of "platform" repo arguments (ie: feed). By making this handle similar to --feed it will be the easiest to implement.