Multi-cursor's setCursor causes a local selection-change event

[byronm]

Calling setCursor on the multi-cursor module to update the position of a remote cursor triggers a selection-change event with source user. To reproduce:

1. Type multiple lines into quill
2. Have client A's cursor on line 0, client B's cursor on line 1
3. On clientB, call setCursor, placing client A's cursor on line 1

This causes a local selection-change event on client B, even though client B's actual cursor did not move.