Describe the bug
Memorypipeline (Distributed) does not delete memories from AzureCognitiveSearch

• When user use the "upload document" it will be saved to AzureCognitiveSearch. When eventually the session will be deleted, the memorypipeline destroy everything else but not AzureCognitiveSearch memories..
• It tries to find an index but does not use the common chatmemory

To Reproduce
Steps to reproduce the behavior:

1. Use Distributed memorypipeline
2. User creates sessions and save documents / memories
3. After discussions, session will be deleted
4. Everything else is destroyed but not the AzureCognitiveSearch memories / document embedings..

Expected behavior
If user deletes the session > it should also delete memories from AzureCognitiveSearch