Implement Serialize and Deserialize for gamepad events

[alice-i-cecile]

What problem does this solve or what need does it fill?

This is useful for input capture and playback of gamepad events, enabling automated testing and advanced input mocking.

What solution would you like?

Derive Serialize and Deserialize for GamepadEvent, GamepadEventRaw, Gamepad, GamepadButtonType and GamepadAxisType.

What alternative(s) have you considered?

Use Serde's https://serde.rs/remote-derive.html in an external crate.

Additional context

This should also likely be done for WindowEvent upstream in winit, but that's likely blocked on rust-windowing/winit#1387

[object71]

Gamepad structs seems to have this behind a feature called serialize #[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))].

[alice-i-cecile]

Ah right! I've made these exact mistake before...