Move System::httpExit to BaseModule->httpExit

- This will ensure headers set in BaseModule->run will be carried in httpExit scenarios
- Deprecate httpExit() method in Core\System

src/Module/Media/Attachment/Browser.php

@@ -80,7 +80,7 @@ class Browser extends BaseModule
 		]);
 
 		if (empty($request['mode'])) {
-			System::httpExit($output);
+			$this->httpExit($output);
 		}
 
 		return $output;

src/Module/Media/Photo/Browser.php

@@ -91,7 +91,7 @@ class Browser extends BaseModule
 		]);
 
 		if (empty($request['mode'])) {
-			System::httpExit($output);
+			$this->httpExit($output);
 		}
 
 		return $output;