LPS-36067 - Correct Selectable Tree state
LPS-36067 - Adjust updateSelectedNodes() to not recurse into child nodes. Adjust restoreNodeState() and related logic to only check nodes in TreeUtil.SELECTED_NODES.
LPS-36067 - Rename variables & methods from selected to checked, to avoid confusion with selected (highlighted) nodes.
LPS-36067 - Source formating.
LPS-36067 - Source formatting