return version of benchmark

[recursix]

Could we implement this?

Benchmark.get_version() -> str

meant to replace this code:

def _get_benchmark_version(benchmark: bgym.Benchmark) -> str:
    benchmark_name = benchmark.name

    if hasattr(benchmark, "get_version"):
        return benchmark.get_version()

    # in the mean time
    if benchmark_name.startswith("miniwob"):
        return metadata.distribution("browsergym.miniwob").version
    elif benchmark_name.startswith("workarena"):
        return metadata.distribution("browsergym.workarena").version
    elif benchmark_name.startswith("webarena"):
        return metadata.distribution("browsergym.webarena").version
    elif benchmark_name.startswith("visualwebarena"):
        return metadata.distribution("browsergym.visualwebarena").version
    elif benchmark_name.startswith("weblinx"):
        try:
            return metadata.distribution("weblinx_browsergym").version
        except metadata.PackageNotFoundError:
            return "0.0.1rc1"
    else:
        raise ValueError(f"Unknown benchmark {benchmark_name}")