Unify implementation of generic boolean checkbox table editor and annotation view-specific implementation
  - Eliminate org.fortiss.tooling.base.ui.annotation.editingsupport.BooleanCellEditor since instead of showning an editor, the icon visualizing the checkbox state is toggled.
  - Rename org.fortiss.tooling.base.ui.annotation.editingsupport.EmulatedNativeCheckBoxLabelProvider -> CheckBoxLabelProviderInsteadSubclassing. It is based on static utility methods provided by org.fortiss.tooling.base.ui.tablecell.CheckBoxLabelProvider (subclassing is not possible due to conflicting required base classes).
refs 2268