This diff introduces changes to the `Dockerfile` to copy the `/shared` directory to the service Docker container.
In a [[ https://linear.app/comm/issue/ENG-1698/moving-of-protos-cpp-and-rust-shared-code-into-a-root-shared-folder | ENG-1698 ]] we have introduced a new directory for the shared objects.
To make the Tunnelbroker built in D4807 and beyond updates, we need to copy the `/shared` folder to the Docker container.