New item creation & submission flow

This month we've updated how new items and created and submitted. These changes should improve the user experience when handling items, removing some of the anxiety associated with creating a new item by allowing users to 'preview' the form before it's created.

Secondly, we've made a small change to how items are handled upon submission. Previously, users were taken back to the app home screen after item submission. For apps with multiple states and the same participant, this was confusing as the user would have to re-open the item to continue working on it in the next state. This is now improved with the item submission redirecting users to the same item in the new state immediately after submission.