Address claiming inactive did methods

[OR13]

GitHub has a good policy on this, worth reading: https://docs.github.com/en/github/site-policy/github-username-policy

GitHub prohibits account name squatting, and account names may not be reserved or inactively held for future use. Accounts violating this name squatting policy may be removed or renamed without notice. Attempts to sell, buy, or solicit other forms of payment in exchange for account names are prohibited and may result in permanent account suspension.

Originally raised in https://github.com/w3c/did-spec-registries/pull/369#discussion_r751274457

[brentzundel]

Github is able to statistically determine that a claimed username has been completely inactive. Is there a similar statistical determination that could be made to determine that a DID Method is inactive?

[kdenhartog]

Yeah this is a tough one, because we want to allow registration of methods early in order to prevent name collisions, but realistically a method is not in "use" until at least one (ideally 2+) people have implemented some form of usage of the method.

What if we said there's a reserved status that can be claimed for up to 3 months on a particular method in order to claim a namespace. At the point when the 3 months have been reached the authors MUST submit evidence that the method continues to be worked on for a 3 month extension or the entry is removed (programmatically)

Additionally only at the point in which at least 1 implementation report has been submitted to the test suite do we allow for permanent registration of the method and at this point it begins it's permanency in the registry.