[PMSH] Create Measurement Group API

[PMSH] Create Measurement Group API

Creates Measurement Group for an associated Subscription
POST: /subscription/{subscription_name}/measurementGroups/{measurement_group_name}
Measurement Group structure:
{
    "measurementGroup": {
           "measurementGroupName": "string",
           "fileBasedGP": 0,
           "fileLocation": "string",
           "administrativeState": "LOCKED",
           "measurementTypes": [

{                           "measurementType": "string"                   }
          ],
          "managedObjectDNsBasic": [

{                           "DN": "string"                  }
          ]
     }
}

Returns:

Success: 201
Invalid Data: 400 when measurement_group_name in URI and body do not match
Not Found: 404 when subscription does not exist to associate measurement group to
Duplicate Data: Measurement group with that name already exists
Error raised for any server failure

Issue-ID: DCAEGEN2-2920

Signed-off-by: egernug <gerard.nugent@est.tech>
Change-Id: I812c5a891e9bed5433000f5da24e2667bf9a5d65