Alternate method is to expose a `SnapDistancesChanged` event in
`IPositionSnapProvider` instead, but I chose this way as an analogue to
`IBeatSnapProvider.BeatDivisor`, which might even make sense to be
exposed as `BindableBeatDivisor` instead of caching that separately.
Tests have started to output too much log content, causing viewing CI
failures to be painfully impossible. Roll back for now.
Fix may be related to
https://github.com/nunit/nunit3-vs-adapter/issues/941, although we don't
use filter.