Fix bugs around mass selection/single selection/drag and drop #146

Job	Run time
🔍 Engine Files Changed / Changed Files	8s
🔍 GUI Files Changed / Changed Files	6s
📦 Package / Build Backend (windows, amd64)	8m 21s
📦 Package / GUI build (linux, amd64)	1m 12s
📦 Package / Build Backend (linux, amd64)	4m 27s
📦 Package / GUI build (windows, amd64)	1m 39s
📦 Package (Optional) / Build Backend (macos, amd64)	28m 42s
📦 Package (Optional) / GUI build (macos, amd64)	11m 23s
📦 Package / Package New IDE (linux, amd64)	5m 35s
📦 Package / Package New IDE (windows, amd64)	10m 24s
IDE Required Checks	1s
📦 Package (Optional) / Package New IDE (macos, amd64)	25m 33s
	1h 37m 31s

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