Laravel components v8 (#2576)

- update actions ci
- include json for 4 spaces tab
- provide output int for process code exit
- adhere to parent type hint of builder
- mailer instance now needs a name, multiple can be instantiated
- getOriginal now uses mutators in the model
- Temporarily loosen MailableInterface requirements. This avoids an immediate BC break for classes in extensions that implement this interface.
- Temporarily provide (and autoload) old symfony translator interface
- make queue exception handler compatible with the contract of L8
- Update phpunit schema for newer version
- Update phpunit assert calls for newer version

src/Console/AbstractCommand.php

@@ -34,7 +34,7 @@ abstract class AbstractCommand extends Command
         $this->input = $input;
         $this->output = $output;
 
-        $this->fire();
+        return $this->fire() ?: 0;
     }
 
     /**