[TECHNICAL] OCS sharing refactor

[joragua]

With the new implementation for OCIS shares listing (#4876), it's necessary to refactor all classes and methods related to the legacy sharing implementation to keep the codebase consistent.

OCS implementation → Use the Ocs prefix.
Graph API implementation → Use the Graph prefix (already done) ✅

TASKS

• Research (if needed)
• Create branch technical/ocs_sharing_refactor
• Development tasks
  • Implement whatever
  • ...
  • Implement unit tests (if needed)
• Code review and apply changes requested
• Design test plan
• QA
• Merge branch technical/ocs_sharing_refactor into master