DEV: patchbot: repeat the syncing buttons at the bottom of the page

DEV: patchbot: repeat the syncing buttons at the bottom of the page

The "Get updates" and "Save changes" buttons only existed at the top
right of the page, while a review session ends at the bottom of the
table: with no button left in sight there, it was way too easy to
forget to save the work. Emit a copy of both buttons and of the status
line at the bottom right, sharing the same handlers; the status
message and the save-button graying are applied to both instances at
once so the two spots always tell the same story.