Rename setGlobalTo to setGlobalToAndRemoveCcAndBcc (#24917)

It's really counter intuitive to have a setter destroy unrelated data,
best to be honest and complete about it.

src/Illuminate/Mail/Mailer.php

@@ -236,7 +236,7 @@ public function send($view, array $data = [], $callback = null)
         // message. This is primarily useful during local development in which each
         // message should be delivered into a single mail address for inspection.
         if (isset($this->to['address'])) {
-            $this->setGlobalTo($message);
+            $this->setGlobalToAndRemoveCcAndBcc($message);
         }
 
         // Next we will determine if the message should be sent. We give the developer
@@ -347,7 +347,7 @@ protected function renderView($view, $data)
      * @param  \Illuminate\Mail\Message  $message
      * @return void
      */
-    protected function setGlobalTo($message)
+    protected function setGlobalToAndRemoveCcAndBcc($message)
     {
         $message->to($this->to['address'], $this->to['name'], true);
         $message->cc(null, null, true);