Function indy_build_get_attrib_request

#[unsafe(no_mangle)]
pub unsafe extern "C" fn indy_build_get_attrib_request(
    command_handle: Handle,
    submitter_did: CString,
    target_did: CString,
    raw: CString,
    hash: CString,
    enc: CString,
    cb: Option<ResponseStringCB>,
) -> Error