Add cargo-auditable config option

[duckinator]

deferred:

• local auto-installation of cargo-auditable (moved to Handle local auto-installation of cargo-auditable #1527)
• throw error when using cargo-auditable=true with non-rust projects (moved to Error when cargo-specific options used for non-cargo projects #1526)

complete:

• use cargo auditable build instead of cargo build if cargo-auditable=true
• install cargo-auditable in workflows if cargo-auditable=true
• tests for both of those
• real-world local test
• real-world CI test

Moved from #1516 because the duckinator/auditable-builds branch name was incompatible with testing dist from a GitHub branch.

[mistydemeo]

Realized there's one mistake in the template setup - something needs to get moved.

[duckinator]

$ cargo audit bin axolotlsay                                                                                                              
    Fetching advisory database from `https://github.com/RustSec/advisory-db.git`
      Loaded 664 security advisories (from /home/puppy/.cargo/advisory-db)
    Updating crates.io index
       Found 'cargo auditable' data in axolotlsay (23 dependencies)

[mistydemeo]

One minor, non-blocking comment. Otherwise, I think we're looking great here! The snapshot tests show the changes we'd want to see in the outputs, too.