Minor shift in container list item height

[cmcode-dev]

Undoubtedly CSS related. I tried fixing this recently but didn't have much luck / time to go further. Seems like when hovering and un-hovering over containers in the extension popup, the CSS causes things to move a few pixels back and forth. Really annoying!

I might try updating to a newer version of Bootstrap to see if that fixes it. If not, I might just abandon Bootstrap in favor of a different CSS framework such as Fomantic/Semantic or Tailwind.