Did not monitor the selection update

[不见月]

I found that when the selection is updated (change from one selection to another, rather than unselected to selected), the property panel on the right is not updated, which will cause the canvas's property settings to fail to achieve the expected effect. After reading the source code, I learned that Fabric.js does not divide the selection update event into two events (selection clear and selection creation), but sends (selection:updated) event to notify the developer that the selection has changed , So just listening (selection:cleared and object:selected) should not be enough.