Keyerror external_id not in field definitions

[Bert-Proesmans]

I cannot request the field external_id when calling get(). Fix or clear error message.

{
    "error": {
        "name": "KeyError",
        "stack": "  File \"/tmp/windmill/wk-default-ebst-phbMa/01928ac4-ebe4-262d-2642-f1af51fdd288/u/bertproesmans/test_pip.py\", line 23, in main\n    .get()\n     ^^^^^\n\n  File \"/tmp/windmill/cache/pip/betterodooapiwrapper==0.1.0/BetterOdooApiWrapper/wrapper.py\", line 530, in get\n    records_by_id = fetch_records(self.model_name, main_ids, nested_fields)\n                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\n  File \"/tmp/windmill/cache/pip/betterodooapiwrapper==0.1.0/BetterOdooApiWrapper/wrapper.py\", line 417, in fetch_records\n    relational_fields = {\n                        ^\n\n  File \"/tmp/windmill/cache/pip/betterodooapiwrapper==0.1.0/BetterOdooApiWrapper/wrapper.py\", line 424, in <dictcomp>\n    if field_defs[field_name]['type'] in {'many2one', 'one2many', 'many2many'}\n       ~~~~~~~~~~^^^^^^^^^^^^\n",
        "message": "'external_id'"
    }
}

[Weltschmerz-dev]

Odoo does not return the field: external_id on a get call.

We should error and advice the user to run .export instead to retrieve the external_id field.