Product Alerts - new information we should store in database

[addison74]

As they are right now the product_alert_price and product_alert_stock tables store only a few information about a subscriber and some important are missing. With the new GDPR rules I would suggest a change in the way OpenMage is dealing with product alerts subscriptions by adding in tables new columns like: IP, browser information, remove date. Comparing these tables with newsletter_subscriber they have more information stored which is much better than nothing.

Let's say someone complains he unsubscribed from a product alert but continue to receive notifications. Having this information stored is easy to prove when the subscription was done.

[elidrissidev]

This sounds interesting, I think it's better if it's put in an Issue. I might give it a try in the future.