PSI Unifier: Use convention-based call for array access expressions when comparing elements by resolved calls

#KT-8312 Fixed

idea/testData/refactoring/introduceVariable/ComplexCallee.kt

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+fun fn(index : Int, list: List<()->Unit>) {
+    when  {
+        index in list.indices -> <selection>list[index]</selection>()
+    }
+}

idea/testData/refactoring/introduceVariable/ComplexCallee.kt.after

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+fun fn(index : Int, list: List<()->Unit>) {
+    when  {
+        index in list.indices -> {
+            val function = list[index]
+            function()
+        }
+    }
+}