Add ACI to /compile output

[davidyuk]

related to aeternity/aepp-sdk-js#1681

The new "aci" property I propose to make in exactly the same format as returned by aesophia_cli and that is used in aepp-calldata library, e.g. an array of contracts and namespaces acis, without encoded_aci, external_encoded_aci fields.

https://github.com/aeternity/aepp-calldata-js#quick-start

$ ./aesophia_cli --create_json_aci ./test/contracts/identity.aes | jq .
[
  {
    "contract": {
      "functions": [
        {
          "arguments": [
            {
              "name": "x",
              "type": "int"
            }
          ],
          "name": "main_",
          "payable": false,
          "returns": "int",
          "stateful": false
        }
      ],
      "kind": "contract_main",
      "name": "Identity",
      "payable": false,
      "type_defs": []
    }
  }
]