Revert "Unused member warning doesn't highlight whole definition anymore"

This reverts commit c659afae0c2d27d78b22a18ca1ca3735cb910a4e.

Fixed #1002209
Fallback to word finder when an error is reported at an offset position
Merge pull request #759 from dragos/issue/revert-wrong-presentation-error-positioning

Revert "Unused member warning doesn't highlight whole definition anymore...