Take Manager as first ctor arg in Watch operation

This makes the constructor consistent with other classes (e.g. Client, GridFS\Bucket) and also ensures that we don't have required parameters trailing optional arguments (i.e. options array).

src/Collection.php

@@ -960,7 +960,7 @@ class Collection
             $options['readConcern'] = $this->readConcern;
         }
 
-        $operation = new Watch($this->databaseName, $this->collectionName, $pipeline, $options, $this->manager);
+        $operation = new Watch($this->manager, $this->databaseName, $this->collectionName, $pipeline, $options);
 
         return $operation->execute($server);
     }

src/Operation/Watch.php

@@ -91,7 +91,7 @@ class Watch implements Executable
      * @param Manager        $manager        Manager instance from the driver
      * @throws InvalidArgumentException for parameter/option parsing errors
      */
-    public function __construct($databaseName, $collectionName, array $pipeline, array $options = [], Manager $manager)
+    public function __construct(Manager $manager, $databaseName, $collectionName, array $pipeline, array $options = [])
     {
         if (isset($options['batchSize']) && ! is_integer($options['batchSize'])) {
             throw InvalidArgumentException::invalidType('"batchSize" option', $options['batchSize'], 'integer');
@@ -119,11 +119,11 @@ class Watch implements Executable
             }
         }
 
+        $this->manager = $manager;
         $this->databaseName = (string) $databaseName;
         $this->collectionName = (string) $collectionName;
         $this->pipeline = $pipeline;
         $this->options = $options;
-        $this->manager = $manager;
     }
 
     /**