Refactoring: make "if-then to safe access" an inspection

idea/testData/inspectionsLocal/branched/ifThenToSafeAccess/noElseBlockAsExpression.kt

@@ -0,0 +1,14 @@
+// PROBLEM: none
+// ERROR: 'if' must have both main and 'else' branches if used as an expression
+// ERROR: Type mismatch: inferred type is Unit but Int was expected
+
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun bar(): Int {
+    val foo = maybeFoo()
+    return if (foo != null<caret>) {
+        foo.length
+    }
+}