"Convert lambda to reference": fix case with extension 'this'

#KT-21999 Fixed

idea/testData/intentions/convertLambdaToReference/extensionOuterScope.kt

@@ -0,0 +1,13 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+class Test {
+    fun test() {
+        with(Any()) {
+            val f = { s: String<caret> -> foo(s) }
+        }
+    }
+
+}
+
+fun Test.foo(s: String) {}