Validate NIF attributes

[evnu]

An unknown NIF attribute should result in an error instead of being ignored. Example:

#[rustler::nif(schedul = "DirtyIo")]
pub fn dirty_io() -> Atom {
    let duration = Duration::from_millis(100);
    std::thread::sleep(duration);

    atoms::ok()
}

Resulting error:

error: custom attribute panicked
  --> rustler_tests/native/rustler_test/src/test_dirty.rs:18:1
   |
18 | #[rustler::nif(schedul = "DirtyIo")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: Unknown attribute 'schedul'. Allowed attributes: ["schedule", "name"]

[scrogson]

👍

[scrogson]

We should also look into proc-macro-error until diagnostics become stable.