Add a Drush Command to Process All Queues

1. +++ b/src/Commands/AdvancedQueueCommands.php
   @@ -95,6 +95,57 @@ class AdvancedQueueCommands extends DrushCommands {
   +   * @option timeout The maximum execution time for each queue. Defaults to 90 seconds.
   

   Do we need to be smarter here. If we have a max execution time setting in PHP it feels like we need to stop the script before it overshoots it. I think this is more problematic than the single queue processor...

2. +++ b/src/Commands/AdvancedQueueCommands.php
   @@ -95,6 +95,57 @@ class AdvancedQueueCommands extends DrushCommands {
   +      if (extension_loaded('pcntl')) {
   +        pcntl_async_signals(TRUE);
   +
   +        pcntl_signal(SIGTERM, function () {
   +          $this->processor->stop();
   +        });
   +
   +        pcntl_signal(SIGINT, function () {
   +          $this->processor->stop();
   +        });
   +      }
   

   This doesn't need to be done in the loop.

Can we convert this to an MR? Thanks!