Close Action - validation/contraints/stats

[dbbaughe]

Currently when we do a Close action, we still allow you to define any actions after + transitions with conditions. We need to provide some validation framework to disallow certain policy configurations that do not make any sense (i.e. you cannot do this to a closed index, so don't even allow it). This can lead to a larger policy validation framework in general, but we have known issues with Close.

We also currently do IndexStats requests in transition which throws an error on closed index. So we need to a) not allow certain conditions (since doc count and size should never increase for a closed index) and b) figure out how to get index_age from a closed index.