What problem does this feature solve?

In webpack, moduleDependency has a method createIgnoredModule that responsible for create ignored module in normal_module_factory.

But in Rspack, we only use RawModule to new ignored module.

More detail see: https://github.com/web-infra-dev/rspack/blob/v1.1.3/crates/rspack_core/src/normal_module_factory.rs#L348-L359

It's would cause a asset-modules/ignored test failed, https://github.com/web-infra-dev/rspack/tree/v1.1.3/tests/webpack-test/configCases/asset-modules/ignore

What does the proposed API of configuration look like?

Align webpack, The trait ModuleDependency add create_ignored_module fn.

pub trait ModuleDependency: Dependency {
  ...
  fn create_ignored_module(&self, context: Context) -> BoxDependency {
    // return a default dependency
  }
}