Improve detection of encrypted config values (by also scanning system.xml and children)

[rutgerrademaker]

In https://github.com/ctidigital/magento2-configurator/blob/develop/Component/Config.php#L178 we can see the config path is matched against values in the metaData

The metadata however only seems to check a module's config.xml

https://github.com/magento/magento2/blob/2.4-develop/lib/internal/Magento/Framework/App/Config/Initial/Reader.php#L72

Many (third party) modules use config files in app/etc/adminhtml/system.xml (and children) to declare the backend_model to be using Magento\Config\Model\Config\Backend\Encrypted

E.g:

https://github.com/Adyen/adyen-magento2/blob/develop/etc/adminhtml/system/adyen_initial_setup.xml#L47
https://github.com/buckaroo-it/Magento2/blob/master/etc/adminhtml/system/account.xml#L40

Currently these fields are not detected