[NFR]: Forms should transform "" to NULL unless explicitly told not to

Database

CREATE TABLE `accommodation` (
  ...
  `website` VARCHAR(60) DEFAULT NULL
  ...

Controller

// Request a transaction
$transaction = $this->transactionManager->get();

$accommodation = new Accommodation();
$accommodation->setTransaction($transaction);

...

$accommodationForm->bind(
    $_POST,
    $accommodation,
    [
        ...
        'website',
        ...
    ]
);

if ($accommodation->create() == false) {
    $transaction->rollback(__('Error has occured while creating accommodation'), $accommodation);
}

...

// no errors, commit changes
$transaction->commit();  

Form

// website input
$website = new Text('website');
$website->setLabel(__('Website'));
/*$website->addValidator(
    new Url(
        [
            "message" => __('Please enter valid website address')
        ]
    )
);*/
$this->add($website);

Expected behavior

DB field should be null when nothing was entered in the field

Actual behavior

DB field is empty string

Details

• Phalcon version: 3.4.0
• PHP Version: 7.2.8
• Operating System: macOS
• Installation type: Compiling from source
• Server: Nginx
• Database: MySQL 8.0.12