Implement "Safe Delete" refactoring for properties

idea/testData/safeDelete/deleteProperty/kotlinProperty/implement8.kt

@@ -0,0 +1,17 @@
+trait A {
+    var <caret>foo: String
+}
+
+trait Z {
+    var foo: String
+}
+
+class B: A, Z {
+    override val foo: String
+        get() {
+            return "B"
+        }
+        set(value: String) {
+
+        }
+}