JS: create new common directory for all generated tests, migrate several tests there

js/js.translator/testData/box/extensionProperty/propertyWithGetterAndSetter.kt

@@ -0,0 +1,26 @@
+package foo
+
+class Test() {
+    var a = 0
+}
+
+var Test.b: Int
+    get() = a * 3
+    set(c: Int) {
+        a = c - 1
+    }
+
+val Test.d: Int get() = 44
+
+fun box(): String {
+    val c = Test()
+    if (c.a != 0) return "fail1: ${c.a}";
+    if (c.b != 0) return "fail2: ${c.b}";
+    c.a = 3;
+    if (c.b != 9) return "fail3: ${c.a}";
+    c.b = 10;
+    if (c.a != 9) return "fail4: ${c.a}";
+    if (c.b != 27) return "fail5: ${c.b}";
+    if (c.d != 44) return "fail6: ${c.d}";
+    return "OK";
+}