Add wp_block_hash field

[suecarmol]

Description

Added the wp_block_hash field and validated if the block has has changed everytime the user logs in

Rationale

We want a system for reviewing users with ignored block status in the case that their block status changes, so that we can evaluate if they should still be added to the allow list.

Phabricator Ticket

T295608

How Has This Been Tested?

Screenshots of your changes (if appropriate):

Types of changes

What types of changes does your code introduce? Add an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Minor change (fix a typo, add a translation tag, add section to README, etc.)

[jsnshrmn]

Thanks for all of your work on this! It is looking really good. There is only one thing that sticks out at me, and it's not actually a problem. It's the fact that the email send is setup directly in the user helper. We're using signals for sending emails in other places, but I don't think there is any advantage to registering a signal here; it has me wondering why I implemented so many of the other signals. Great work!