No major API change here, only in the outliner restriction column
variables (e.g., show_restrict_column_selectable > show_restrict_column_select).
* Get rid of _INSTANCE (introduced on b1af682001).
* Differentiate (everywhere but the API) between HIDE (temporary) and VIEWPORT (global).
* Use the expected icon for restrict viewport (same as objects and modifiers).
* selectable > select