Scratch-blocks: Drop radius changes

[MegaApuTurkUltra]

The drop radius gets bigger as a block is pulled away. I'm not sure if this is by design, but I think drop radius should be constant. This happens for all types of blocks.

[tmickel]

We did it intentionally, here: https://github.com/LLK/scratch-blocks/commit/fa992e9f863df2c9b25bcfc140e6105cf41e26b0

To fix this bug: https://github.com/LLK/scratch-blocks/issues/290 (video in there).

There might be a way to fix that some other way. I think we need to consider reducing SNAP_RADIUS in general, too... @rachel-fenichel

[kvackkvack]

There might be a way to fix that some other way. I think we need to consider reducing DRAG_RADIUS in general, too... @rachel-fenichel

Yes, I agree with this. I'm fine with the drop radius increasing as long as it's not by _that_ much. Might make it very annoying for greatly nested operators.
EDIT: Perhaps also do it only for "pants" blocks, which seem to be the only type of block where this is a problem?

[MegaApuTurkUltra]

Also some way to disable snapping (eg shift-drag) would be helpful with such a large drop radius

[tmickel]

@MegaApuTurkUltra We're addressing this in #635 - give it another try sometime, please!