Provider enrollment: "Provider Statement" UI improvements

[brainwane]

On step 5. ("Provider Statement") of the provider enrollment process:

• The Date field should display a date picker to make it easier for the user to select today's date (and to avoid slip-ups by people who are from countries where the usual sequence of writing dates is day-month-year). We probably should not automatically fill in today's date, because this page is like the signature page of a legal document, so we do want to make the user actively choose (and thus figuratively write) the current date.
• Next to the "Provider Name" field, we should display a reminder of the user's, to help the user type it in (this is helpful when the user can't remember whether the version they've submitted has a middle name or middle initial, whether to include stuff like "Dr." or "M.D.", etc.)
• Next to "Provider Title" we should also display the user's title, as a reminder, plus an explanation of what that is (Dr./Mr./Ms.? Position, like "Physician"? Something else?)

[cecilia-donnelly]

Per conversation with @jvasile, we should display today's date as a read-only field. We don't need them to enter it.

[cecilia-donnelly]

Raising the priority of this after conversation with @jvasile.