user_b_analytics_data table should be renamed conversation_analytics_data, as well as all related functions/classes

[danmash]

user_b_analytics_data will no longer be related to user b.

• refactor all the codebase to remove user_b from all functions/classes
• make a migration to rename the table
• move this functionality to the new folder named analytics.

[danmash]

blocked by #416, don't. want to refactor till then