Remove dependency on Cargo

[JanLikar]

Depending on Cargo makes the build time unreasonable.

Last time I heard it Cargo team was not too keen on including cargo-clone into Cargo, that's why it doesn't make sense anymore to depend on Cargo.

Everything we use Cargo for could be re-implemented with minimal dependencies. Alternatively, we could call the cargo binary to perform some of the tasks.

[JanLikar]

This could be implemented using tame-index or crates-index