[OCIS][OC Storage] etags are not updated on file operations

[dpakach]

Several file operations on ocis do not update the etags of the files

• renaming file/folder doesn't changes the etag of parent

  apiWebdavEtagPropagation1/moveFileFolder.feature:20
  apiWebdavEtagPropagation1/moveFileFolder.feature:21
  apiWebdavEtagPropagation1/moveFileFolder.feature:308
  apiWebdavEtagPropagation1/moveFileFolder.feature:323

• moving a file/folder from one folder to another doesn't changes etag of destination folder

  apiWebdavEtagPropagation1/moveFileFolder.feature:39
  apiWebdavEtagPropagation1/moveFileFolder.feature:40
  apiWebdavEtagPropagation1/moveFileFolder.feature:58
  apiWebdavEtagPropagation1/moveFileFolder.feature:59
  apiWebdavEtagPropagation1/moveFileFolder.feature:93
  apiWebdavEtagPropagation1/moveFileFolder.feature:94
  apiWebdavEtagPropagation1/moveFileFolder.feature:305
  apiWebdavEtagPropagation1/moveFileFolder.feature:306

• renaming a file/folder inside another folder doesn't changes etag of parent folder

  apiWebdavEtagPropagation1/moveFileFolder.feature:74
  apiWebdavEtagPropagation1/moveFileFolder.feature:75
  apiWebdavEtagPropagation1/moveFileFolder.feature:140
  apiWebdavEtagPropagation1/moveFileFolder.feature:141
  apiWebdavEtagPropagation1/moveFileFolder.feature:167
  apiWebdavEtagPropagation1/moveFileFolder.feature:168
  apiWebdavEtagPropagation1/moveFileFolder.feature:236
  apiWebdavEtagPropagation1/moveFileFolder.feature:23

[phil-davis]

I tried PR https://github.com/owncloud/ocis/pull/1192 that had sleeps to make sure that the original file and the rename/move/overwrite... happen at least 2 seconds apart. That ensures that the Unix timestamp is different. That did not help make any of the scenarios pass. So the issue is not just about that sort of timing.