Subject controlled vocabulary for Ephemera Folders doesn't expand/collapse.

[eliotjordan]

We used bootstrap-select to do this before, but the library's since changed and our old code is no longer working.

[tpendragon]

The vocab wasn't in staging, so I added it, but all the subject categories are showing up expanded and can't be collapsed.

[tpendragon]

Bootstrap-select has been upgraded and our old overrides in app/assets/javascripts/bootstrap_select_dropdown.js are no longer working.

I'm having a hard time fixing it - hiding the <li>s results in the select dropdown resizing wrong.

Things I've tried:

Rewrote the JS to get the optgroup from the class rather than a data attribute, and trigger off that. (resulted in big empty spaces post-collapse)
Tried snapappointments/bootstrap-select#2700 to fix the empty area - still happened.
Gave up.

[hackartisan]

I think this may be working now. Here's what it looks like for me locally

[hackartisan]

Oh wait they aren't grouped right.

[hackartisan]

I got as far as successfully replicating the issue, hooray