Service provider and other cleanup

- Removed old 'exposeTranslations' system to instead use new component
 option system.
- Extracted validation rules into their own service provider.
- Cleaned up some formatting/comments in the repos.

app/Config/app.php

@@ -124,6 +124,7 @@ return [
         BookStack\Providers\EventServiceProvider::class,
         BookStack\Providers\RouteServiceProvider::class,
         BookStack\Providers\CustomFacadeProvider::class,
+        BookStack\Providers\CustomValidationServiceProvider::class,
     ],
 
     /*