[Vue-2.x] Dynamic Range Slider fixes

[Jade-GG]

This PR contains a few updates to the DynamicRangeSlider in the Vue2 branch:

• Make sure ranges stay within range
• Hide the slider if the range is nonsensical (null or min/max equal)
• Add an extra class list for the outer div
• Turn the title into a slot, as god intended

I figure this branch is probably EOL because Vue2 is, but I also figure it's worth a try.