feat(plugin): add fake-js builtin plugin for JavaScript module transformation
- Add new `rolldown_plugin_fake_js` crate with JavaScript parsing and transformation capabilities
- Implement FakeJsRolldownPlugin with support for AST manipulation, code generation, and dependency analysis
- Add parser, visitor, and codegen modules for handling JavaScript module transformations
- Include support for import/export analysis, type parameter handling, and filename resolution
- Add BindingFakeJsPluginConfig for configuring sourcemap, cjs_default, and side_effects options
- Register FakeJs as builtin plugin with "builtin:fake-js" identifier in plugin system
- Add TypeScript bindings and plugin index exports for JavaScript integration
perf(module_loader): use ArcStr for importer_id to avoid string copy (#7922)
Since StableModuleId already stores an ArcStr internally, we can share it directly instead of copying the string into a CompactStr.