add "retired" to resource status

[smarru]

The current status only includes post-production, but we also need to add retired for machines no longer available. This status ensures the resource description is not necessarily purged from the inventory but marked as retired and stays in the inventory.

[joestubbs]

i agree with adding this!

[joestubbs]

we should clarify the definitions of pre-production, production and post-production in the documentation as well.

• pre-production: some system components are available (possibly to friendly users) but not in production.
• production: all system components are available and are generally available.
• post-production: some components may still be available but some may not be or may be in an otherwise degraded state.
• retired: the system is no longer available; the resource description is included for posterity.