[Memory] more ready to use memory component

[liyin2015]

Current memory can be built with ready to use components, such as local db / cloud db, and any retriever. Some users want more higher-level (out-of-the-box) solution that can be potentially usable in 80% use cases.

This further ready to use code will be located here: https://github.com/SylphAI-Inc/LightRAG/blob/main/lightrag/lightrag/components/memory/memory.py

We will first need a good design, and we can potentially learn some good use case patterns from https://memgpt.ai/

What are your use cases if you want support for memory?