J2K: get/set-methods converted to properties (but lot of TODOs left)

j2k/testData/multiFile/GetterAndSetterUsages/1.kt

@@ -6,6 +6,6 @@ class AAA {
     }
 
     fun bar(b: B) {
-        println(b.YY)
+        println(b.yy)
     }
 }

j2k/testData/multiFile/GetterAndSetterUsages/2.kt

@@ -1,9 +1,9 @@
 internal class B {
     fun foo(a: AAA) {
         a.x = a.x + 1
-        YY += "a"
+        yy += "a"
     }
 
-    var YY = ""
+    var yy = ""
         private set
 }