UI - Exit Popup

We have a way for the user to view their already entered key-value pairs, and we have a way for the user to enter new ones. The last screen we need to create, is the exit/confirmation screen.

In this screen, we are asking the user if they want to output the key-value pairs they have entered in the stdout pipe, or close without outputting anything.

{{#include @code/tutorials/json-editor/src/ui.rs:exit_screen}}

The only thing in this part that we haven't done before, is use the Clear widget. This is a special widget that does what the name suggests --- it clears everything in the space it is rendered.