This diff is a part of the flat diffs stack to transform the current Tunnelbroker project into a Rust app by calling the current C++ codebase from Rust. The related transition task is [[ https://linear.app/comm/issue/ENG-1072 | ENG-1072 ]].
This diff creates a Cargo `build.rs` file which builds and links the current C++ codebase to the Rust application.
Related Linear task and discussion: [[ https://linear.app/comm/issue/ENG-2061/change-the-build-system-for-tunnelbroker-to-build-the-current-c | ENG-2061 ]]
**CI Notice:**
The CI will fail on these diffs until the end of the stack with the changes to CI build commands. This stack will be landed all in one to prevent CI from failing on diffs out of this stack.