[Calendar] Snap to current during resize

The recently added option to support never using event boxes and snapping to grid was a great and well welcome addition to my project.

Another feature I immediately thought of that would be useful for end users and be more responsive, is the ability to snap the event duration to the grid but also to the current start/end time the event is currently set to.

For example - let’s say I have an event that is set for 10:45-12:30, this can now display beautifully, however, when attempting to resize the event from the start for instance, only 10:30 and 11:00 are valid options when snapToGrid is true. But what if I changed my mind? I don’t actually want to resize it, I am unable to cancel my selection and have to remodify the event’s duration manually or whatever other method my project allows me to use.