View summary of edits to a submission

Not a priority in the near future and we need to validate this is a need, but I wanted to capture our ideas around editing submissions & a summary view.

## User story
As a PM making multiple edits to a submission,
I want to view a clean summary with my edits highlighted,
So that I can easily see what has changed without being distracted by the input fields.

## **Other considerations**
- Need to be careful with language preview and summary are different functions. Maybe we call it “Edit summary” or “view changes” or "view activity"
- Maybe you could show edits inline/ same as form filling but we layer things on where the changes are or give the ability to navigate the next change

No files, tests, or entry points are identified. First validate whether PMs need an edit-summary view and resolve the terminology and presentation choices described under Other considerations; done means an agreed, clean summary that highlights submission edits without distracting from input fields.

Written by the indexing model from the issue text.