Everywhere: Add config and cache page

Add config database table and enable crud page.
Also add cache controller, model and view and routes for these pages.

Make the JavaScript display a message when changing the state of
development mode.

config.php.example

@@ -15,7 +15,7 @@ return [
 	'MAIL_USERNAME' => '',
 	'MAIL_PASSWORD' => '',
 
-	'DEVELOPMENT_MODE' => '',
-	'DEVELOPMENT_MODE_TOKEN' => '',
-	'DEVELOPMENT_MODE_ZONE' => '',
+	'CLOUDFLARE_ENABLED' => '',
+	'CLOUDFLARE_TOKEN' => '',
+	'CLOUDFLARE_ZONE' => '',
 ];