handle lastUpdateTime for Wopi implementation

* get the last updated time from the stored object's storage
* improve perf on loading content from stored object's storage: keep the
response in cache

src/Bundle/ChillWopiBundle/src/Service/Wopi/ChillDocumentManager.php

@@ -147,8 +147,7 @@ final class ChillDocumentManager implements DocumentManagerInterface
      */
     public function getLastModifiedDate(Document $document): DateTimeInterface
     {
-        // TODO: Add column 'LastModifiedDate' in StoredObject entity
-        return $document->getCreationDate();
+        return $this->storedObjectManager->getLastModified($document);
     }
 
     public function getLock(Document $document): string

src/Bundle/ChillWopiBundle/src/Service/Wopi/ChillWopi.php

@@ -13,6 +13,7 @@ namespace Chill\WopiBundle\Service\Wopi;
 
 use ChampsLibres\WopiLib\Contract\Service\DocumentManagerInterface;
 use ChampsLibres\WopiLib\Contract\Service\WopiInterface;
+use DateTimeInterface;
 use loophp\psr17\Psr17Interface;
 use Psr\Cache\CacheItemPoolInterface;
 use Psr\Http\Message\RequestInterface;
@@ -88,11 +89,14 @@ final class ChillWopi implements WopiInterface
                     'UserFriendlyName' => $userIdentifier,
                     'SupportsUpdate' => true,
                     'SupportsRename' => true,
+                    'SupportsFolder' => false,
                     'DisablePrint' => false,
                     'AllowExternalMarketplace' => true,
                     'SupportedShareUrlTypes' => [
                         'ReadOnly',
                     ],
+                    'LastModifiedTime' => $this->documentManager->getLastModifiedDate($document)
+                        ->format(DateTimeInterface::ATOM),
                     'SHA256' => $this->documentManager->getSha256($document),
                     'UserInfo' => (string) $this->cache->getItem($userCacheKey)->get(),
                 ]