Include crate name in symbol name

[jonas-schievink]

Currently, the symbol name includes the Cargo package, the defmt tag and data, and the "disambiguator", which is a crate-unique identifier. However, a Cargo package can contain many crates, so to be safe we should also include the crate name (via CARGO_CRATE_NAME) in the symbol name.

Another unclear edge case is what happens when crates are renamed in a downstream Cargo.toml. It seems like this might let you pull in two crates with the same crate and package name, but a different Cargo version, so maybe that should also be included.