Add independent Lora load/unload

[RossAscends]

• adds param box for Lora scale in editor
• moves editor button to top of model list section
• adds lora model selector, and buttons to independently load/unload loras
• changes toastr responses to include error details

I think my repo wasn't synced to main before I made the commits on my end, so it claims to be "3 commits ahead and 2 commits behind", but I was working from the latest main commit as installed in my ST, so it should be safe to merge all diffs from this PR into main without losing anything.

[RossAscends]

oh it looks like the only conflict is an addition of of new a const, so yeah that's fine to merge in.