[interop] Add Support for JSDoc Documentation (#435)

* wip: docs

* completed doc integration

* made fields final and added const for performance

* resolved issues

* refactored `generateFromDocumentation` and redundant annotation transform

refactored `generateFromDocumentation` for nullable docs and removed unnecessary add for annotations in `transformer.dart`

Author: nikeokoronkwo

web_generator/lib/src/ast/base.dart

@@ -5,6 +5,7 @@
 import 'package:code_builder/code_builder.dart';
 
 import '../interop_gen/namer.dart';
+import 'documentation.dart';
 import 'types.dart';
 
 class GlobalOptions {
@@ -65,6 +66,8 @@ abstract class NamedDeclaration extends Declaration {
   @override
   abstract String name;
 
+  abstract Documentation? documentation;
+
   ReferredType asReferredType([List<Type>? typeArgs, String? url]) =>
       ReferredType(
           name: name, declaration: this, typeParams: typeArgs ?? [], url: url);