Harmonize Sync and Workspace

Sync and the workspace view in the main UI have similar roles but each lets you do things the other doesn't. Notably, Sync is missing a diff, while the Workspace view won't do all the Sync magic.

We should harmonize the two and if possible reuse code for a better user experience.

Components of this:
* Improve commit message / details to be similar to workspace
* Add diff capabilities in Sync page (making each file an expandable panel to see the diff)
* Add a "Sync" button in the main UI
* Improve output of things in the main UI

The outcome will be:
* Basic mode users get more functionality from their fairly-simple page
* Expert users can get all the "Sync" benefits from a UI that should provide a superset of Basic Mode