Synchronize the UUri used by Rust and C++

If we want to ensure interoperability between examples in different languages, it would be better to use the same UUri.
Here is what I'm using in Rust now: https://github.com/eclipse-uprotocol/up-zenoh-example-rust/pull/4/files#diff-a990dc6fb21d6b911a96ebc9bf1db1bf13d9692eab3c114cc7819a6172953622R34

Maybe we can update the UUri with a more practical naming. Feel free to suggest a better one.