Switch to need_macro!()

Data macros (host::data::macros) are currently hardcoded, which had led to a lot of code duplication. A macro exists (`need_macro!`) to generate the required macros, however there is an issue with the eager expansion of `$crate::`.

See issue: https://users.rust-lang.org/t/crate-being-expanded-too-eagerly-for-nested-macros/7592
