Bugfixes for mark installed/mark planned button

Fixes netbox-community#13712 and netbox-community#13806.

Not super happy with the fix here, because it doesn't address the
underlying problem, which is that the toggleConnection() typescript function hardcodes
which CSS classes should be added/removed. Probably a more permanent fix would be
to stop applying CSS classes on the table view, and instead apply attributes
for cable/interface state, and then use CSS to apply colours based on
interface state, but this is a quite involved process. But it does at least
fix things in the here and now.