JS: replace all usages of @native annotation with external modifier, in tests, stdlib, etc

js/js.translator/testData/box/inlineMultiFile/_common.kt

@@ -1 +1 @@
-@native public fun parseInt(s: String, radix: Int = 10): Int = noImpl
+external public fun parseInt(s: String, radix: Int = 10): Int = noImpl

js/js.translator/testData/box/inlineMultiFile/tryCatch2.kt

@@ -136,7 +136,7 @@ inline fun <T, R> T.performWithFail2(job: (T)-> R, failJob: (e: RuntimeException
     }
 }
 
-@native object Number {
+external object Number {
     fun parseInt(str: String): Int = noImpl
 }