Convert FoldInitializerAndIfToElvisIntention to inspection and decrease severity to INFO

#KT-19643 Fixed

idea/testData/inspectionsLocal/foldInitializerAndIfToElvis/NotExit.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+fun foo(p: List<String?>): Int? {
+    val v = p[0]
+    <caret>if (v == null) bar()
+    return v?.length
+}
+
+fun bar(){}