Add filters for revoked & expired keys in the admin panel

[saurabh0719]

Hi @florimondmanca,
I've gone through older issues and I hope this isn't a repeat.

Is your feature request related to a problem? Please describe.
This isn't a problem. However, I think it would be useful to add Filters for the django admin panel, through which the admin can filter out Revoked or Expired keys.

Describe the solution you'd like
I would be happy to add some custom filters or modify the default ones to add this feature.