implement a new updateBarcode method

[melanierogan]

We need to create the patron in order to know the recordNumber (patron id), we can then set the patron's barcode as the patron id using updateBarcode.

Based on:

• Testing sign up currently fails within login script
• I think the point of failure happens around validateCredentials as this expects a barcode and password, we have not set a barcode at patron creation
• We found current format of self registered patron's barcode is initially based on recordNumber

Helpful to know: The format of barcode with self registered patron object on sierra

{
    "id": 12345,
    "barcodes": [
        "12345"
    ]
}

related to work on https://github.com/wellcomecollection/wellcomecollection.org/issues/8071 and https://github.com/wellcomecollection/wellcomecollection.org/issues/7896