Add `tuning` to language bindings

The `bindings/` folder contains bindings for iOS, Java, Python, Swift. Add the [`tuning`  option](https://github.com/infojunkie/verovio/blob/b0cfcccd9f24fe7d9c5ba0aa175e82dd4258c7fc/src/options.cpp#L1827-L1829) to all of those. It is already [recognized by the JavaScript interface](https://github.com/infojunkie/verovio/blob/80f4545853d655c684d448143230f01987d4daf0/demo/index.html#L17-L20).
