Currently the format of each metadata inconsistency object is the following:

{
   "type":"TYPE",
   "description":"DESC",
   "shard":"SHARD",
   "ns":"NSS",
   "info":{
      "..."
   }
}

In particular the shard and the namespace field are mandatory for all inconsistencies types.
To make the format more generic and extensible we should instead adopt the following:

{
   "type":"TYPE",
   "description":"DESC",
   "details":{
      "shard":"SHARD",
      "namespace":"NSS",
      ...
   }
}

In this format the only required field are type and description, everything else is optional and should go into the details section.

Additionally as part of this ticket we should create a static map of TYPE->DESCRIPTION that can be used implicitly when creating new inconsistency object.