[TECHNICAL] Rely on `R` permission and ignore `resharing` capability for oCIS accounts

[JuancaG05]

Currently, to know whether we should show the share button or not, we rely on the R permission of the file AND the resharing capability. The resharing capability has been set to false by default in oCIS servers (https://github.com/owncloud/ocis/issues/8842), so we shouldn't look at it anymore. There can be the case in which some files in the Shares space come with the R permission, but none of them should be resharable. So, several acceptance criteria here:

• [ ] Keep the same behaviour as now in oC10 servers
• [ ] Rely only on R permission and don't look at resharing capability in oCIS servers
• [ ] Never show the share button in the Shares space (only available in oCIS)

TASKS

• [ ] Research (if needed)
• [ ] Create branch technical/remove_resharing_capability_ocis
• [ ] Development tasks
  • [ ] Implement whatever
  • [ ] ...
  • [ ] Implement unit tests (if needed)
• [ ] Code review and apply changes requested
• [ ] Design test plan
• [ ] QA
• [ ] Merge branch feature/remove_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: https://github.com/owncloud/ios-app/issues/1353