Cope with crate renames

`data` is a common word, so we should expect that sometimes the crate will be renamed. We should deal with this in macros and indirect through `Cargo.toml`.

Inspect the macros and Cargo.toml handling first to understand how the crate name is referenced and how a renamed crate should be supported. Done means the macros work when the crate is renamed and dependency handling goes through Cargo.toml as requested; the issue names no tests or specific entry points.

Written by the indexing model from the issue text.