Introduce "Call chain on collection should be converted into 'Sequence'"

So #KT-15476 Fixed

idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/nullable.kt.after

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+fun test(list: List<Int>?): List<Int>? {
+    return list
+            ?.asSequence()
+            ?.filter { it > 1 }
+            ?.map { it * 2 }
+            ?.toList()
+}