add trailing slash to restore_path for trashed directories

[JF-Cozy]

Add a trailing / to restore_path (path of the parent folder) when trashing files and directories. This prevents false positives when querying the trash of shared drives with similar names — without it, a $gte: "/Shared Drives/Test" query also captures files from "/Shared Drives/Test 2/...".

No impact on RestoreDir / RestoreFile — DirByPath uses path.Clean which strips trailing slashes, and path.Join normalizes paths.

App must change fetch from

    Q(FILES_DOCTYPE)
      .where({
        dir_id: TRASH_DIR_ID,
        type,
        name: { $gt: null },
        restore_path: { $gte: path, $lt: path + '\ufff0' }
      })

to

    Q(FILES_DOCTYPE)
      .where({
        dir_id: TRASH_DIR_ID,
        type,
        name: { $gt: null },
        restore_path: { $gte: path + '/', $lt: path + '\ufff0' }

[shepilov]

what will be for the files with "/" as an oldpath? I think we should keep root unchanged