Add new ascsers_cluster gatherer

[arbulu89]

New ascsers_cluster gatherer, which gathers details about this type of clusters. Open for other name options The gatherer doesn't require any argument.

To use, simply:

facts:
  - name: cluster_details
    gatherer: ascsers_cluster

This is what it returns (once approved, this will be commented in the gatherers docs):

#{
  "PRD": #{
    "ensa_version": "ensa1/ensa2/unknown",
    "instances": [
      #{
         "name" : "ASCS00", // 2nd value of the InstanceName value
         "instance_number: "00", 
         "virtual_hostname": "sapascs00", // 3rd value of the InstanceName value
         "filesystem_based": true/false, // if the instance resource group has a FileSystem resource
         "local": true/false // if the instance is running locally (sapcontrol returns a positive response for GetProcessList)
      },...
   ]
  },
  "DEV": #{
     "ensa_version": "ensa1/ensa2/unknown",
     "instances": [
...
  }
}

FYI: @yeoldegrove

[yeoldegrove]

@arbulu89 as discussed, I added two new return values that are useful as check input.

[arbulu89]

@yeoldegrove thank you so much! the changes look good to me. I'm waiting for some additional review from my team, but i think we can merge it the next days for sure