[BUGFIX] Fix exit codes in AbstractClientRequestCommand

AbstractClientRequestCommand just returns the response form
RequestService by casting it to an integer. However, the return
value must be negated since the RequestService returns true (1)
on success and false (0) on failure.

Exit code 1 is now also returned if the API responded with an error.

src/Command/AbstractClientRequestCommand.php

@@ -67,7 +67,10 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             ->setRaw($input->getOption('raw') !== false)
             ->setDefaultAuthMethod($this->defaultAuthMethod);
 
-        return (int)(new RequestService(
+        // RequestService returns a boolean for whether the request was successful or not.
+        // Since we have to return an exit code, this must be negated and casted to return
+        // 0 on success and 1 on failure.
+        return (int)!(new RequestService(
             $requestConfiguration,
             new ConsoleWriter($io, $this->getMessages(), $this->resultFormat)
         ))->run();

src/Service/RequestService.php

@@ -77,6 +77,7 @@ public function run(): bool
                 $this->consoleWriter->writeFailure(
                     (string)($content['error_description'] ?? $content['message'] ?? 'Unknown (Status ' . $status . ')')
                 );
+                return false;
             }
         } catch (ExceptionInterface|\InvalidArgumentException $e) {
             $this->consoleWriter->error('An error occurred: ' . $e->getMessage());