Add test methods and data base on raw fir builder test data

compiler/visualizer/testData/rawBuilder/expressions/branches.kt

@@ -0,0 +1,90 @@
+//                            foo.a: Int
+//                            │ fun (Int).compareTo(Int): Int
+//                            │ │ foo.b: Int
+//                            │ │ │  foo.a: Int
+//                        Int │ │ │  │      foo.b: Int
+//                        │   │ │ │  │      │
+fun foo(a: Int, b: Int) = if (a > b) a else b
+
+fun bar(a: Double, b: Double): Double {
+//  Nothing
+//  │   bar.a: Double
+//  │   │ fun (Double).compareTo(Double): Int
+//  │   │ │ bar.b: Double
+//  │   │ │ │
+    if (a > b) {
+//      fun io/println(Double): Unit
+//      │       bar.a: Double
+//      │       │
+        println(a)
+//             bar.a: Double
+//             │
+        return a
+    } else {
+//      fun io/println(Double): Unit
+//      │       bar.b: Double
+//      │       │
+        println(b)
+//             bar.b: Double
+//             │
+        return b
+    }
+}
+
+fun baz(a: Long, b: Long): Long {
+//  Nothing
+//  │
+    when {
+//      baz.a: Long
+//      │ fun (Long).compareTo(Long): Int
+//      │ │ baz.b: Long
+//      │ │ │    Nothing
+//      │ │ │    │
+        a > b -> {
+//          fun io/println(Long): Unit
+//          │       baz.a: Long
+//          │       │ 
+            println(a)
+//                 baz.a: Long
+//                 │
+            return a
+        }
+//              Nothing 
+//              │      baz.b: Long
+//              │      │
+        else -> return b
+    }
+}
+
+fun grade(g: Int): String {
+//         String    
+//         │     grade.g: Int
+//         │     │   
+    return when (g) {
+//      Int                  
+//      │  Int  String       
+//      │  │    │            
+        6, 7 -> "Outstanding"
+//      Int  String     
+//      │    │          
+        5 -> "Excellent"
+//      Int  String
+//      │    │     
+        4 -> "Good"
+//      Int  String    
+//      │    │         
+        3 -> "Mediocre"
+//      fun (ranges/IntRange).contains(Int): Boolean
+//      │  Int           
+//      │  │fun (Int).rangeTo(Int): ranges/IntRange
+//      │  ││ Int  String
+//      │  ││ │    │     
+        in 1..2 -> "Fail"
+//                   String  
+//                   │       
+        is Number -> "Number"
+//              String   
+//              │        
+        else -> "Unknown"
+    }
+}