message: hint overwrite option to user in IO errors
diff: @@ -113,7 +113,7 @@ void PhysicalCopyToFile::Combine(ExecutionContext &context, GlobalSinkState &gst
  partition_key_map[i]->values, trimmed_path, fs);
  string full_path = fs.JoinPath(hive_path, "data_" + to_string(l.writer_offset) + "." + function.extension);
  if (fs.FileExists(full_path) && !allow_overwrite) {
  - throw IOException("failed to create " + full_path + ", file exists!");
  + throw IOException("failed to create " + full_path + ", file exists! Enable ALLOW_OVERWRITE option to force writing");
  }
  // Create a writer for the current file
  auto fun_data_global = function.copy_to_initialize_global(context.client, *bind_data, full_path);
  @@ -186,7 +186,7 @@ unique_ptr<LocalSinkState> PhysicalCopyToFile::GetLocalSinkState(ExecutionContex
  string output_path =
  fs.JoinPath(file_path, StringUtil::Format("out_%llu", this_file_offset) + "." + function.extension);
  if (fs.FileExists(output_path) && !allow_overwrite) {
  - throw IOException("%s exists", output_path);
  + throw IOException("%s exists! Enable ALLOW_OVERWRITE option to force writing", output_path);
  }
  res->global_state = function.copy_to_initialize_global(context.client, *bind_data, output_path);
  }
  @@ -199,7 +199,7 @@ unique_ptr<GlobalSinkState> PhysicalCopyToFile::GetGlobalSinkState(ClientContext
  auto &fs = FileSystem::GetFileSystem(context);
  if (fs.FileExists(file_path) && !allow_overwrite) {
  - throw IOException("%s exists", file_path);
  + throw IOException("%s exists! Enable ALLOW_OVERWRITE option to force writing", file_path);
  }
  if (!fs.DirectoryExists(file_path)) {
  fs.CreateDirectory(file_path);
  @@ -208,7 +208,7 @@ unique_ptr<GlobalSinkState> PhysicalCopyToFile::GetGlobalSinkState(ClientContext
  fs.ListFiles(
  file_path, [&n_files](const string &path, bool) { n_files++; }, FileOpener::Get(context));
  if (n_files > 0) {
  - throw IOException("Directory %s is not empty", file_path);
  + throw IOException("Directory %s is not empty! Enable ALLOW_OVERWRITE option to force writing", file_path);
  }
  }
  