Replace XXXReturn with Result<XXXSuccess, XXXError>

... in function signatures.

These breaking changes aim at improving usability by allowing users
to take advantage of Rust error management features sur as `ok_or`,
`map_err`, `expect` and the `?` operator. See the `examples` and
`tutorials` to get an idea of the impacts.
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rustfmt

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test nightly

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passed #79189
test stable

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