Updating `menu` version to combine context and interface

[ryan-summers]

This PR updates the version of menu used to have a single context that uses the embedded-io traits and is writable.

This PR was done to understand if the context and interface of menu could be combined.

The main downside observed is that the Settings structure isn't carried around as a top-level resource, but is hidden behind a few layers of indirection because of the necessary lifetime borrow abstractions.

[ryan-summers]

I would say we leave the current implementation as-is and wait and see what direction menu ends up going. If it gets released to crates.io in this state, we can merge this PR and port over, but there's no burning need to at this point unless we want to publish serial-settings (which I don't think is stable enough to publish yet).

[jordens]

Agreed.

[ryan-summers]

This version of menu did not end up being merged, Instead, the code currently in the repo is closer. As such, I'm closing this PR as this work is no longer required.