Some of those are still Copy&Paste problems.
This PR:
* Only cleans the legacy incorrect code, doesn't change or improve the
"action" logic.
* Remove the redundant `$('.toggle.button').on('click')`, now
`$('.show-panel.button').on('click')` handles that kinds of buttons
Actually, there is only one correct "toggle button" in code, the one on
the webhook page.
No need to backport.