[XB] Start Conversation Allowed/Disallowed Groups 2.0.0

Provides control over who can initiate private conversations with users based on user group permissions.

Features:​

• User Privacy Settings: Members can customize which user groups are allowed to start conversations with them. Administrators can also configure these settings for users.
• Group-Based Restrictions: Administrators can enforce restrictions that limit specific user groups from starting conversations with other groups. These limits can be overridden by a user's privacy settings if they have the required permissions.