#3082979 Jetpack Cloud: Update styling and functionality of the BackupDelta component

Changes proposed in this Pull Request

• Brings the BackupDelta component into functional spec
• Brings the BackupDelta component into rough design spec (will improve CSS methodologies later if needed)

Testing instructions

Note: These changes are only for daily backup views.

Load up the backups page for a date/site which has various types of changes, including post creation/deletion, media upload/deletion, plugin installation/removal, theme installation/removal.

Some general things to look at:

• The entire BackupDelta section should only appear for days that have a change of some sort.
• Media changes should look sensible and reflect what happened on the site, including an accurate count in the “bubble” below the media.
• Edited/deleted posts should appear in the list
• Themes/plugins that were installed/deleted should appear in the list, and look sensible.
• The metadata at the very bottom of the component should appear accurate, showing number diffs from the last backup to this one.
• Significant design departures from the below image should be noted 🙂

Notes (will add more as I think of them):

• The uploads count in the metadata at the end “looks” incorrect, but this is actually counting the files created in the wp-content/uploads directory, so it includes the resized images. We might want to call this “media files” or something less confusion than “uploads”, which a user is likely to associate with images they uploaded, rather than files generated on the server.