feat: make traits public in the CAN module

[maximeborges]

Summary

Making OwnedPeripheral, RxPin, TxPin public and sealed so they can be used to make abstraction layers in your own application.

Checklist

• All new or modified code is well documented, especially public items
• No new warnings or clippy suggestions have been introduced - CI will deny clippy warnings by default! You may #[allow] certain lints where reasonable, but ideally justify those with a short comment.

Note

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