fix: add missing entity id in FsEventMapper::getFromQueue() (#196)

The FileSystemListener background job tries to delete events from the queue if the home-dir of the user cannot be found (e.g. because the user account has been removed):

https://github.com/rotdrop/nextcloud-app-context-chat/blob/f8566e58d3a384d67615163ef0ac4cf13f276746/lib/BackgroundJobs/FileSystemListenerJob.php#L104

However, this call to `FsEventMapper::delete()` cannot succeed if the entity id is missing, as is currently the case because ATM `FsEventMapper::getFromQueue()` omits the id in its result "entities" (which are in fact then only partial entities).

Another way to fix this would be to use `FsEventMapper::deleteByContent()` instead.

Signed-off-by: Claus-Justus Heine <himself@claus-justus-heine.de>

Author: rotdrop

lib/Db/FsEventMapper.php

@@ -72,7 +72,7 @@ public function insertRow(string $type, string $userId, int $nodeId): Entity {
 	 */
 	public function getFromQueue(int $limit): array {
 		$qb = $this->db->getQueryBuilder();
-		$qb->selectDistinct(['user_id', 'type', 'node_id'])
+		$qb->selectDistinct(['id', 'user_id', 'type', 'node_id'])
 			->from($this->getTableName())
 			->setMaxResults($limit);