Adding quotas on alarms

+ Quotas can be set at a user level or a project level
+ Quotas are set via config options
+ Quotas default values are None (unlimited) for backward compatibility
+ Creates a new client side error OverQuota that is raised when the
  quota is reached
+ If OverQuota is raised, return a HTTP 403 (forbidden) response.

Change-Id: Ib9876013f8eb930875a91699a6b3314f8f1b1b47
Implements: blueprint quotas-on-alarms
Co-Authored-By: Ala Rezmerita <ala.rezmerita@cloudwatt.com>
Merge "Adding quotas on alarms"