Implement 'when' transformations (flatten, introduce subject, eliminate subject)

idea/resources/intentionDescriptions/FlattenWhenIntention/after.kt.template

@@ -0,0 +1,17 @@
+when (n) {
+    1 -> {
+        res = "one"
+    }
+    2 -> {
+        res = "two"
+    }
+    3 -> {
+        res = "three"
+    }
+    4 -> {
+        res = "four"
+    }
+    else -> {
+        res = "???"
+    }
+}