[feat]: Update Identity page to include date fields and validations

[brandonlenz]

As a claimant I would like to be able to enter dates for the remaining fields:

• date of birth (if not imported)
• Immigration document issue date
• • Immigration document expiration date

(see related TODOs in https://github.com/trussworks/unemployment-insurance-modernization-demo/blob/main/src/pages/identity/identity.tsx)