[dart2wasm] Copy VM's map and set factory transformers

Transform factory calls to default map and set classes to the
constructor calls to the classes to improve kernel.

Also remove some redundant null checks in VM's transformer.

`source_map_simple_optimized_test.dart` is updated: with improved kernel
wasm-opt now eliminates the `testMain` function, so the stack trace
doesn't mention it.

Fixes https://github.com/dart-lang/sdk/issues/60343.
Tested: minor refactoring in VM doesn't need testing. Wasm tested with
existing tests.
Change-Id: Ie448d1374ff0e1b278859f22bc250899e0e4cfd0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/416640
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Ömer Ağacan <omersa@google.com>

tests/web/wasm/source_map_simple_optimized_test.dart

@@ -14,7 +14,6 @@ const List<(String?, int?, int?, String?)?> frameDetails = [
   ('errors_patch.dart', null, null, '_throwWithCurrentStackTrace'),
   ('source_map_simple_lib.dart', 16, 3, 'g'),
   ('source_map_simple_lib.dart', 12, 3, 'f'),
-  ('source_map_simple_lib.dart', 39, 5, 'testMain'),
 ];
 
 /*