[schema] Dedup db parameter_value schema object

"parameter_value" is the same as the "value" definition
defined in the commons schema

See #74

beat/core/schema/database/1.json

@@ -105,23 +105,9 @@
       "type": "object",
       "patternProperties": {
         "^[a-zA-Z_][a-zA-Z0-9_-]*$": {
-          "$ref": "#/definitions/parameter_value"
+          "$ref": "../common/1.json#/definitions/value"
         }
       }
-    },
-
-    "parameter_value": {
-      "oneOf": [
-        {
-          "type": "string"
-        },
-        {
-          "type": "number"
-        },
-        {
-          "type": "boolean"
-        }
-      ]
     }
 
   }