Ability to edit guest fields when registering

[dwhitig]

Description
When a primary (host) registrant adds guests and notices they either missed answering a question or incorrectly entered something, they have to delete the guest registration and start over. Would be nice if they could edit it.

Steps to Reproduce
Set up an event to take guest registrations.
Set up several questions to ask about each guest.
During registration, add a couple of guest records. For one of the records, leave one of the questions unanswered.

Impact
Registrant may choose to leave bad or missing data.
Registration takes longer because they need to delete the guest and readd.

Desired behavior:
Have an Edit button that allows the registrant to edit and resave the guest information

Acceptance Criteria
Able to edit an existing guest record and change or add information during the registration process before final check out.