Make the text boxes in edit-structure Ui editable

[sujitv19196]

Problem

Current Edit-structure Ui does not allow user to delete images or text We want to merge the functionality of the edit-structure and edit-chapter UIs

Solution

• convert the static text boxes into the editable text boxes that are in the edit-chapter Ui
• deletions and edits to the text boxes should be reflected in the Ui and the I-Notes

Mockup: https://www.figma.com/proto/OVKDEecxHeRruHC42ADXAQ/Edit-Structure?node-id=1-2&scaling=min-zoom&page-id=0%3A1

[angrave]

BTW Suggest you could develop & merge this on a different branch (e.g. experiment), so that staging branch can continue to be whats going into production in the near future.

We have another experimental server that could be used to host this.

[sujitv19196]

implemented