If then to elvis: handle nullability even with implicit receiver

So #KT-22741 Fixed

idea/testData/intentions/branched/ifThenToElvis/nullableResultWithImplicitReceiver.kt

@@ -0,0 +1,7 @@
+// IS_APPLICABLE: false
+
+class Something {
+    fun nullable(): Int? = null
+}
+fun Something?.nullable(value: Int): Int? =
+    <caret>if (this == null) value else nullable()