PrefName: break MPI cache

[wesrowe]

Description

User story

As a Veteran, I want my changes to my preferred name to immediately be visible in VA.gov, so that it doesn't look like the success message on the Profile page was incorrect (thus harming my trust in VA and VA.gov).

Notes

• Wes was on a call with Trevor Borsaw on 11/19, learned that there is a method to break MPI cache

Possible tasks:

• Discuss current "update preferred name" with AuthExp (Tom Harrison)
• Get blessing from Identity to break cache

Acceptance criteria

• The preferredName field on the User object changes upon save of preferred name
• QA review

[wesrowe]

From Planning 11/20:

• Ask Tom/Trevor about where and how to do this, and might Tom/AuthExp do it for us?
• UX risk: browser cache might still cause some users to see the old pref name