Refactoring: "introduce when subject" is now an inspection

idea/testData/inspectionsLocal/branched/introduceWhenSubject/whenWithNegativePatterns.kt.after

@@ -0,0 +1,8 @@
+fun test(obj: Any): String {
+    return <caret>when (obj) {
+        !is Iterable<*> -> "not iterable"
+        !is Collection<*> -> "not collection"
+        !is MutableCollection<*> -> "not mutable collection"
+        else -> "unknown"
+    }
+}