Add support of comments in asymmetric returns

idea/testData/codeInsight/codeTransformations/branched/folding/asymmetricReturn/simpleIfWithComments.kt

@@ -0,0 +1,5 @@
+fun test(n: Int): String {
+    <caret>if (n == 1) return "one"
+    // comment
+    return "two"
+}

idea/testData/codeInsight/codeTransformations/branched/folding/asymmetricReturn/simpleIfWithComments.kt.after

@@ -0,0 +1,4 @@
+fun test(n: Int): String {
+    <caret>return if (n == 1) "one" else "two"
+    // comment
+}