message: Fix :vs and :vsp (vertical split) commands
  Fix the vertical split commands, which were broken when the logic for
  the showOpenDialog command was added by PR
diff: @@ -72,6 +72,10 @@ export class FileCommand extends node.CommandBase {
  return;
  } else if (this._arguments.name === '') {
  + if (this._arguments.position === FilePosition.NewWindow) {
  + await vscode.commands.executeCommand('workbench.action.splitEditor');
  + return;
  + }
  const fileList = await vscode.window.showOpenDialog({});
  if (fileList) {
  const doc = await vscode.workspace.openTextDocument(fileList[0]);
  