refactor: use english for routes, parameters and internal messages

src/Security/OAuth2/EpClient.php

@@ -74,11 +74,11 @@ class EpClient
 
         $code = $request->query->get('code');
         if (null === $code || '' === $code) {
-            throw new AuthorizationRequestException('Die Antwort von myep enthielt keinen Code.');
+            throw new AuthorizationRequestException('The callback from myep carried no authorization code.');
         }
 
         if (null === $expectedState || $request->query->get('state') !== $expectedState) {
-            throw new AuthorizationRequestException('Der state-Parameter passt nicht zur Sitzung.');
+            throw new AuthorizationRequestException('The state parameter does not match the one this session started with.');
         }
 
         return $this->getProvider()->getAccessToken('authorization_code', ['code' => $code]);
@@ -107,13 +107,13 @@ class EpClient
                 ['headers' => ['Accept' => 'application/json']],
             ));
         } catch (ClientExceptionInterface $e) {
-            throw new UserinfoUnavailableException('userinfo konnte nicht abgerufen werden.', previous: $e);
+            throw new UserinfoUnavailableException('The userinfo endpoint could not be reached.', previous: $e);
         }
 
         $userinfo = json_decode((string) $response->getBody(), true);
 
         if (!\is_array($userinfo)) {
-            throw new UserinfoUnavailableException('userinfo lieferte keine lesbare Antwort.');
+            throw new UserinfoUnavailableException('The userinfo endpoint returned an unreadable payload.');
         }
 
         return $userinfo;