Civi::queue() - Add support for 'template' queues

Civi::queue() - Add support for 'template' queues

Overview
--------

Suppose you are in the habit of making separate queue-instances for
different batches of work.  However, you want to allow the sysadmin to
configure options like `type`, `batch_limit`, and `retry_interval`.

Solution: Make a template

After
-----

```php
// Use the API to register a template, eg
\Civi\Api4\Queue::create()->setValues([
  'name' => 'template-name',
  'is_template' => TRUE,
  ...
])->execute();

// Later, create a queue from the template
$q = Civi::queue('new-queue', ['template' => 'template-name']);
```