JS: rename @Before to @BeforeTest and @After to @AfterTest for better JUnit compatibility

libraries/kotlin.test/js/it/src/test/kotlin/MainTest.kt

@@ -5,11 +5,11 @@ var value = 5
 
 class SimpleTest {
 
-    @Before fun beforeFun() {
+    @BeforeTest fun beforeFun() {
         value *= 2
     }
 
-    @After fun afterFun() {
+    @AfterTest fun afterFun() {
         value /= 2
     }
 

libraries/kotlin.test/js/src/main/kotlin/kotlin/test/Annotations.kt

@@ -29,9 +29,9 @@ public annotation class Ignore
 /**
  * Marks a function to be invoked before each test.
  */
-public annotation class Before
+public annotation class BeforeTest
 
 /**
  * Marks a function to be invoked after each test.
  */
-public annotation class After
+public annotation class AfterTest