Make the Chat Widget's Confirmation Message on Contact Form Customizable

As of now, the confirmation message when a customer leaves their contact information is a generic "Thanks for reaching out".

See https://support.zendesk.com/hc/en-us/articles/360041076314-Can-I-edit-the-ticket-confirmation-message-from-the-Web-Widget-.

We'd like to see the ability to customize this message, as we want to cater it to our brand and our mission.