Support for conversations with message history

[leila-messallem]

Description

Adding chat functionality with message history.

• Added an optional chat_history parameter to the invoke method of the LLMInterface.
• The chat_history is a dict with role and content keys, where role can be either "user" or "assistant".
• Added a system_instruction parameter to the LLM class instantiation (meaning that you have to create a separate LLM instance for each use case. The motivation being that on vertexai, system_instruction is set on the GenerativeModel object, so separated from the question prompt).
• Added a summary of the chat history to the query embedding (so that the relevant context gets included in the embedding).

Type of Change

• New feature
• Bug fix
• Breaking change
• Documentation update
• Project configuration change

Complexity

Complexity: High

How Has This Been Tested?

• Unit tests
• E2E tests
• Manual tests

Checklist

The following requirements should have been met (depending on the changes in the branch):

• Documentation has been updated
• Unit tests have been updated
• E2E tests have been updated
• Examples have been updated
• New files have copyright header
• CLA (https://neo4j.com/developer/cla/) has been signed
• CHANGELOG.md updated if appropriate

[stellasia]

I'm wondering if we should allow the user to use a different LLM for summarization. I'm thinking users might want to use a "small" LLM for this simple task, and use a "better" one for the Q&A part. But we can leave it for a later improvement.

[leila-messallem]

@CodiumAI-Agent /update_changelog

[CodiumAI-Agent]

Changelog updates: 🔄

2024-12-19

Added

• Support for conversations with message history, including a new message_history parameter for LLM interactions.
• Ability to include system instructions and override them for specific invocations.
• Summarization of chat history to enhance query embedding and context handling.

Changed

• Updated LLM implementations to handle message history consistently across providers.
• Enhanced prompt templates to support chat history summarization and conversation context.

to commit the new content to the CHANGELOG.md file, please type:
'/update_changelog --pr_update_changelog.push_changelog_changes=true'

[stellasia]

Nice work! 🥳🥳

Thanks for dealing with all the issues, especially the vendor specificity 🙏

[CodiumAI-Agent]

Changelog updates: 🔄

2024-12-20

Added

• Support for conversations with message history, including a message_history parameter for LLM interactions.
• Summarization of chat history to improve query embedding and context handling.
• Ability to include and override system instructions for specific LLM invocations.

Changed

• Updated LLM implementations to handle message history consistently across providers.

to commit the new content to the CHANGELOG.md file, please type:
'/update_changelog --pr_update_changelog.push_changelog_changes=true'