[LG-16741] Fix last logged in on duplicate profile page

[joshuaalley25]

🎫 Ticket

Link to the relevant ticket:
LG-16741

🛠 Summary of changes

We were previously populating the 'last logged in' field, displayed on the duplicate profile page, with the last_signed_in on from the EmailAddress model. It is inaccurate for a few reasons so we updated it to be populated with last_authenticated_at from the ServiceProviderIdentity.

📜 Testing Plan

Provide a checklist of steps to confirm the changes.

• Step 1: Recreate duplicate account scenario by creating two accounts and signing into a SP requiring Facial Match
• Step 2: You will be redirected to a duplicate accounts page as shown in the image below
• Step 3: You should see the last login date populated

👀 Screenshots

[jmdembe]

Can we write a test where we can prove that last_sign_in updates accordingly?

[joshuaalley25]

I wonder if it is appropriate here. We aren't writing any code that updates or creates the data. We are simply displaying it so I can test that we are grabbing the data that we say we are grabbing but checking for updates of that data from session to session would be tested elsewhere.