Override/Implement: Use function body template when generating functions with default body

#KT-11807 Fixed

idea/testData/codeInsight/overrideImplement/traitGenericImplement.kt.after

@@ -4,6 +4,6 @@ interface G<T> {
 
 class GC<T>() : G<T> {
     override fun foo(t: T): T {
-        <selection><caret>throw UnsupportedOperationException()</selection>
+        <selection><caret>throw UnsupportedOperationException("not implemented") //To change body of created functions use File | Settings | File Templates.</selection>
     }
 }