Extract Function: Allow to extract local variables which are used outside of extracted fragment

idea/testData/refactoring/extractFunction/controlFlow/default/defaultCFWithExtraVars.kt

@@ -0,0 +1,17 @@
+// PARAM_TYPES: kotlin.Int, Comparable<Int>
+// PARAM_TYPES: kotlin.Int, Number, Comparable<Int>, Any
+// PARAM_DESCRIPTOR: value-parameter val a: kotlin.Int defined in foo
+// PARAM_DESCRIPTOR: val b: kotlin.Int defined in foo
+// SIBLING:
+fun foo(a: Int) {
+    val b: Int = 1
+
+    <selection>if(a > 0) {
+        println(a)
+    }
+    val c: Int
+    println(b)</selection>
+
+    c = 1
+    println(c)
+}