Improve admin UI performance

[jdavcs]

When editing permissions on a role, on main it takes ~28 seconds to load the central panel of the page. On test it's instant. This is, most likely, due to the huge difference between the number of users on main and test. Yet, only 1000 are displayed in the drop down in both cases. Most likely, this will be an issue only on the three big instances; however, it's still a performance issue that, I think, might stem from sub-optimal db access.

Describe the bug A clear and concise description of what the bug is.

Galaxy Version and/or server at which you observed the bug Galaxy Version: 24.0.rc1 Commit: cc7e36e13007151000b19ecaccb39528557c7bda

Browser and Operating System Operating System: fedora 34 Browser: Chrome

To Reproduce Steps to reproduce the behavior:

1. Go to 'admin/roles'
2. Click on a role > edit permissions
3. wait. wait. wait...

[martenson]

fwiw half of the admin interface on usegalaxy.org needs such wait time

[jdavcs]

Thanks, good to know! Certainly not 24.0-related or critical. I'll add similar stuff to this issue then.