Restrict Further Sharing of Shared Chats in Chat API

[vineetshar]

Description:
Currently, the chat-sharing feature permits secondary sharing, where users with whom a chat is shared (e.g., User B) can share it further with others (e.g., User C). This creates potential privacy and control concerns, as the original chat creator may not intend for additional sharing.

Proposed Solution:

• Implement restrictions within the Chat API that prevent secondary users from sharing the chat further.
• Only the original creator (User A) should retain the permission to share access.

Tasks:

• Update the chat-sharing logic to restrict further sharing permissions to only the chat creator.
• Add checks within the API to verify user permissions before allowing share actions.
• Test the sharing restrictions to confirm expected behaviour.

Acceptance Criteria:

• Only the original creator can share a chat.
• Secondary users (those with whom a chat is shared) are restricted from sharing the chat further.