bring back lockfiles for bindings

[selfisekai]

previously 9eb22a5 removed Cargo.lock files citing https://doc.rust-lang.org/cargo/faq.html#why-do-binaries-have-cargolock-in-version-control-but-not-libraries.

this argumentation is valid for the library as used from another rust/cargo project, but the C API produces a binary rather than a library (from the text's standpoint). I think similar with the JS API too.

(aside, maybe this repository should use cargo workspaces)

[inikulin]

Good point. PR is welcome