Add specialized copying routines

[ap--]

We could incrementally add support for faster copy.
This would mean, in pado.shutil we'd switch to a different copy implementation based on the (IN, OUT) FileSystem class of fsspec...

Something like this maybe better integrated:

import os
from pado.images import ImageProvider
from pado.io.files import urlpathlike_to_fs_and_path

def write_download_script(
    image_provider: ImageProvider, destination: str | os.PathLike
) -> str:
    """
    get a bash-script for downloading images

    Parameters
    ----------
    image_provider:
        thats what you want to copy
    destination:
        local path

    Returns
    -------
    str:
        the bash script
    """
    finished_file = os.path.join(destination, "done")
    script = [
        "#!/bin/sh",
        "FILES=$(cat << EOF",
    ]
    for urlpath in image_provider.df.urlpath:

        fs, path = urlpathlike_to_fs_and_path(urlpath)
        assert "gs" in fs.protocol
        if fs.storage_args or fs.storage_options:  # type: ignore
            raise NotImplementedError("todo")
        bucket_url = f"gs://{path}"
        script.append(bucket_url)
    script.extend([
        "EOF",
        ")",
        f"echo \"$FILES\" | gsutil -m cp -I {destination!s}"
        f"touch {finished_file}",
        "",
    ])

    return "\n".join(script)