Validate JSON rows

For example, given the following example Contacts template:

Column key	Date type	Validations
first_name	Alphabetical	Must be mapped
last_name	Alphabetical	Must be mapped
date_of_birth	Date MM/DD/YYYY
id	Number	Unique

The following request would result in the provided response:

// Example request
{
  "template_key": "contacts",
  "rows": [
        { "id": 1, "last_name": "Smith" },
        { "id": 2, "first_name": "Charlie", "last_name": "Johnson9", "date_of_birth": "May 10th" },
        { "id": 3, "first_name": "Mary", "last_name": "Goel" },
        { "id": 3, "first_name": "Audrey", "last_name": "Goel" },
        { "id": 4, "first_name": "Tom", "last_name": "Jackson", "phone_number": "555-555-5555" }
    ]
}

// Example 200 response
{
    "error_rows": [
        {
            "index": 0,
            "errors": {
                "first_name": {
                    "code": 8000,
                    "message": "Template column must be mapped"
                }
            }
        },
        {
            "index": 1,
            "errors": {
                "last_name": {
                    "code": 37,
                    "message": "Must be only letters"
                },
                "date_of_birth": {
                    "code": 3,
                    "message": "Must match MM/DD/YYYY date format"
                }
            }
        },
        {
            "index": 2,
            "errors": {
                "id": {
                    "code": 1000,
                    "message": "Data is duplicate in unique column"
                }
            }
        },
        {
            "index": 3,
            "errors": {
                "id": {
                    "code": 1000,
                    "message": "Data is duplicate in unique column"
                }
            }
        },
        {
            "index": 4,
            "errors": {
                "phone_number": {
                    "code": 8001,
                    "message": "Invalid template column"
                }
            }
        }
    ]
}