Attempting to adjust a slider with too low beat divisor can cause broken slider

[peppy]

• Create slider
• Set beat divisor to 1/1
• After placement, adjust slider's SV high enough such that its duration is less than a 1/1 tick (like so)
• Attempt to adjust slider path

I think we at very least want checks in place such that modifications are rejected if the slider's length is too short.

https://user-images.githubusercontent.com/191335/188382729-4c669e6c-aa01-4e3c-a938-c492104ddd4d.mp4