getAccountPointees: allow to query only active names

[davidyuk]

To don't fetch outdated data. Currently, it is defined as

    "/accounts/{accountId}/names/pointees": {
      "get": {
        "deprecated": false,
        "description": "Get account pointees",
        "operationId": "GetAccountPointees",
        "parameters": [
          {
            "name": "accountId",
            "in": "path",
            "description": "The account that names point to",
            "required": true,
            "schema": {
              "$ref": "#/components/schemas/AccountAddress"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Returns the name the active and inactive name pointees",
            "content": {
              "application/json": {
                "schema": {
                  "allOf": [
                    {
                      "type": "object",
                      "required": [
                        "data"
                      ],
                      "properties": {
                        "data": {
                          "type": "array",
                          "items": {
                            "$ref": "#/components/schemas/Pointee"
                          }
                        }
                      }
                    },
                    {
                      "$ref": "#/components/schemas/PaginatedResponse"
                    }
                  ]
                }
              }
            }
          },
          "404": {
            "description": "Not Found",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/NotFoundResponse"
                }
              }
            }
          }
        }
      }
    },

A query example:
https://mainnet.aeternity.io/mdw/v3/accounts/ak_2nAajTCx2kme7MWJTr2VwQABN9LPBusU4shH4HmXPQhHjf2x77/names/pointees