_db.form() Resource Improvements

[JailtonAraujo]

It would be cool if there was the possibility for the query results to return a hierarchical structure for forms that are linked. For example, if there is a person form and a contact subform, I can return the person records and each record bring the respective contacts.

Exemple of the final structure returned:

[
    {
        "name": "my name",
        "age": 26,
        "active": true,
        "contacts": [
            {
                "type":"mail",
                "name": "mymail@mail.com"
            },
            {
                "type":"phone_number",
                "name":"(24) 68254-1466"
            }
        ]
    },
    {
        "name": "my name 2",
        "age": 36,
        "active": true,
        "contacts": [
            {
                "type":"mail",
                "name": "mail@mail.com"
            },
            {
                "type":"phone_number",
                "name":"(33) 45623-1466"
            }
        ]
    }
]