"Move to next/previous instance of current selection" don't act like in vscode

[huyz]

It would be nice if "Move to next/previous instance of current selection" acted like vscode's "Move Last Selection To Next/Previous Find Match".

The problem is that "Move to next/previous instance of current selection" resets the previous multiple cursors. Instead of resetting, the current cursor should move (similar to #17 (comment)) and the other cursors should remain.
This way, we have a way to skip an instance when creating multiple cursors, which is a feature that I think all implementations of multiple cursors handle.