[wip] command for getting user file information

[icewind1991]

• [ ] requires #37865

follow up from #37525 this time focused on all files a user has access to

Currently shows

• all storages a user has access to, their size and free space
• versions, trashbin sizes for home storage

example output:

admin

  available storages:
  - /admin/: home storage (3.5 GB in files, 3.3 MB in trash, 164 B in versions, 271.3 GB free)
  - /admin/files/gf/: groupfolder 1 (0 B used, 271.3 GB free)
  - /admin/files/source/: external storage 1 (8.6 MB used, 1.1 TB free)
 use occ info:file:space <path> to get more details about used space