Live preview footer: "Discard" changes and "Cancel"/"Close" button

[thupsi]

Right now the Live Preview's edit pane footer is this:

I think it would be better UI/UX if it was updated to be more inline with slideout footers:

Pros:

• More consistent with slideout UI.
• Increased visibility of unsaved changes.
• Ability to discard changes without closing the preview (this is the most important point for me).

Also, it would be nice if the Cancel/Close action was also available in the "standalone preview mode" and it redirected to the previewed element on the front end: Right now, there are some plugins that link to this route (Palette and Quick edit), but it's a bit cumbersome if you make edits (or not) and then want to return to the page.