Refactor domain release with DeleteCandidate procedure

[vohmar]

Current solution adds deleteCandidate status to the domain registration that has passed its 'delete at' date. DeleteCandidate is set for random time for up to 24hrs. This is in conflict with domain regulations as the domain registration should not exist after delete at date has passed (no one owns that domain after that) and the deleteCandidate procedure just blocks the domain for being registered for a random period of time.

So the procedure should be as follows

1. domain is expired
2. after 15 days (configurable) domain is removed from zone
3. after another 30 days (configurable) domain registration is deleted (archived) and the domain is added to blocked/deleteCandidate list for a random period of time between current moment and end of the day (estonian time)
4. after the random period of time has passed the domain name is removed from blocked/deleteCandidate list and released for regular registration.