Revert "* SelectionManager: Added 'SelectableInstance'."
Revert "* SelectionManager: Added 'SelectableInstance'."

This reverts commit bc96d185425b986e966e5b37d19c80058ab4cc9b.

chbfiv/fabric-engine-old,errordeveloper/fe-devel,chbfiv/fabric-engine-old,errordeveloper/fe-devel,chbfiv/fabric-engine-old,chbfiv/fabric-engine-old,errordeveloper/fe-devel,errordeveloper/fe-devel,errordeveloper/fe-devel,chbfiv/fabric-engine-old,errordeveloper/fe-devel,chbfiv/fabric-engine-old,errordeveloper/fe-devel,chbfiv/fabric-engine-old