10-7959f-1: add prefill

[marywang2]

As a logged in user, I want to see my info filled in so I don't have to manually input all my info when I go to register for FMP.

figma link - this is the claims figma but the design is still the same

• intro screen message for signed in users
• personal information prefilled and uneditable (name, DOB, masked SSN), per design system guidance
  • prefill message appears at top of mailing address screen with address information filled out
  • fields filled out from profile where applicable
• phone/email screen is not prefilled
• home address is not prefilled

Acceptance Criteria

• Given a logged in user is accessing the FMP registration form
• When the user starts filling out the form
• Then fields that can be filled out from the user's profile should be prefilled, such as name, DOB, SSN and mailing address