Convert FoldInitializerAndIfToElvisIntention to inspection and decrease severity to INFO

#KT-19643 Fixed

idea/testData/inspectionsLocal/foldInitializerAndIfToElvis/CommentInBlock.kt

@@ -0,0 +1,8 @@
+fun foo(p: List<String?>): Int {
+    val v = p[0]
+    <caret>if (v == null) {
+        // return -1 if null
+        return -1
+    }
+    return v.length
+}