(EAI-236): Evaluation CLI generate data, CLI implementation, and `ConversationService` refactor

[mongodben]

Jira: https://jira.mongodb.org/browse/EAI-236

Changes

• [x] Functions to load and generate conversation test cases
• [x] CLI command generate
• [x] Create our implementation of mongodb-chatbot-eval that calls chatbot-server-mongodb-public
• [x] [BREAKING CHANGE] Refactor ConversationsService to take in system prompt at conversation creation rather than at service creation. Also, update docs and quick start guide accordingly.
  • makes it easier to use with the eval framework and better coding practice i think
• [x] Add UserMessage?.contextContent and use in our implementation. will help with RAG evaluation to be tracking this explicitly in DB.

Notes

• [x] Must wait until merge of https://github.com/mongodb/chatbot/pull/339 and rebase on top of this.

[mongodben]

Let's make sure to indicate in the release notes for our next server release that this contains the breaking system prompt change in the createConversation() method.

yep! will do release + docs publish now so that quick start is up to date.