fix(napi-derive): generate correct types for HashMap with RandomState argument

[sapphi-red]

For

#[napi]
fn get_mapping_with_hasher() -> HashMap<String, u32, FxBuildHasher> {
  let mut map = HashMap::with_hasher(FxBuildHasher);
  map.insert("a".to_string(), 101);
  map.insert("b".to_string(), 102);
  map
}

the following types were generated

export declare function getIndexMappingWithHasher(): any

This PR fixes that.