Slack bot - add a conversional feature

[wpak-ai]

• Summarize a channel discussion for a day/week/month
• Summarize issue discussions context for a day/week/month
• Summarize mentions for a person for a day/week/month
• Summarize RAG search via multiple parameters (intelligently fill missing params or use default ones if not given) for all namespaces
  Restrict access to just Slack members who are part of cppalliance channel.