The API allows adding categories with empty name

[josecelano]

Check this test:

#[tokio::test]
async fn it_should_allow_adding_empty_categories() {
    // code-review: this is a bit weird, is it a intended behavior?

    let mut env = TestEnv::new();
    env.start(api::Version::V1).await;

    if env.is_shared() {
        // This test cannot be run in a shared test env because it will fail
        // when the empty category already exits
        println!("Skipped");
        return;
    }

    let logged_in_admin = new_logged_in_admin(&env).await;
    let client = Client::authenticated(&env.server_socket_addr().unwrap(), &logged_in_admin.token);

    let category_name = String::new();

    let response = client
        .add_category(AddCategoryForm {
            name: category_name.to_string(),
            icon: None,
        })
        .await;

    assert_added_category_response(&response, &category_name);
}