Introduce obsolete/archived status for plugins

[westonruter]

When a plugin is closed ​via Ipstenu:

It becomes invisible to everyone but you. No one can download it, no one can see it, and it’s not listed anywhere on your profile. As far as a user is concerned, it vanishes.

Has there been consideration given to an archived or obsolete status for plugins? I think there would be value in having plugins still available for historical purposes, especially for feature plugins that get merged.

[Ipstenu]

Duplicate of #2860.

Moving this to https://meta.trac.wordpress.org/ticket/2860

We're going to track in another way :)

[SergeyBiryukov]

Related: #2627.