message: client: Pass all arguments to ExecuteCommandRequest
  Previously, only the first argument was passed.
diff: @@ -723,7 +723,7 @@ class ExecuteCommandFeature implements FeatureHandler<ExecuteCommandRegistration
  if (data.registerOptions.commands) {
  let disposeables: Disposable[] = [];
  for (const command of data.registerOptions.commands) {
  - disposeables.push(Commands.registerCommand(command, (args: any[]) => {
  + disposeables.push(Commands.registerCommand(command, (...args: any[]) => {
  let params: ExecuteCommandParams = {
  command,
  arguments: args
  