[TECHNICAL] Rely on `resharing` capability

[JuancaG05]

The resharing capability has been set to false by default in oCIS servers (owncloud/ocis#8842), and we realised that we're sending the wrong permissions within the OCShare object. We always give it share permission although the server doesn't allow it. We also show the Can share switch enabled when editing a share. So, several acceptance criteria here:

• Send correct permissions within the OCShare object, depending on resharing capability
• If resharing capability is false, disable the Can share switch for shares

TASKS

• Research (if needed)
• Create branch technical/rely_on_resharing_capability_ocis
• Development tasks
  • Set correct permissions in OCShare object
  • Disable Can share switch when resharing is false
  • Implement unit tests (if needed)
• Code review and apply changes requested
• Design test plan
• QA
• Merge branch feature/rely_on_resharing_capability_ocis into master

[TheOneRing]

Correction:
The code enabling resharing for the share jail was removed. The capability will always be false.
Our main concern is to disable resharing for the sharejail in any case. Files in the sharejail might provide the R permission but we should never offer the option to share them.

[jesmrec]

iOS related: owncloud/ios-app#1353

[jesmrec]

Follow up: owncloud/ocis#9681

[jesmrec]

Rolling version not following the R: propfinded items with R are not allowed to be reshared.

[jesmrec]

Update: owncloud/ocis#9681 (comment)

R does not mean resharing. We have to mind the capability.

If capability is false (as it is expected in oCIS servers from now on):

• The share permission should be removed from default in private shares (now, it is 31)
• The Can Share permission should be gone or disabled in the sharing dialog