KJS: implement Throwable in Kotlin instead of use it as alias of JS Error

* Make it an inheritor of JS Error. Otherwise, Chakra engine doesn't fill stack trace of exception; In other engines inheritance has some good effects too.
* Copy all properties from internally created instance of JS Error

 #KT-6985 Fixed
 #KT-2328 Fixed
 #KT-8019 Fixed
 #KT-10911 Fixed

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java

@@ -2953,6 +2953,12 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
                 KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("js/js.translator/testData/box/expression/try"), Pattern.compile("^([^_](.+))\\.kt$"), TargetBackend.ANY, true);
             }
 
+            @TestMetadata("exceptionToString.kt")
+            public void testExceptionToString() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/box/expression/try/exceptionToString.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("multipleCatchBlocks.kt")
             public void testMultipleCatchBlocks() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/box/expression/try/multipleCatchBlocks.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -19805,13 +19805,7 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
         @TestMetadata("throwableImpl.kt")
         public void testThrowableImpl() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/specialBuiltins/throwableImpl.kt");
-            try {
-                doTest(fileName);
-            }
-            catch (Throwable ignore) {
-                return;
-            }
-            throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
+            doTest(fileName);
         }
 
         @TestMetadata("valuesInsideEnum.kt")