refactor(llm): enhance a string of graph query method

[imbajin]

Main Changes

• enhance vid k-neighbor query
• enhance property k-neighbor query
• limit edges to avoid super vertex expanding
• fetch vids only instead of fetch all vertices (with property)
• refactor the code logic / simplify it
• enhance extract keywords logic with @vichayturen
• filter single char & avoid match meanness words (compare distance)
• compress duplicate property output
• use better path for LLM to get the graph related info
• .....

[imbajin]

Follow #84 (merge it first), and maybe include some vid matching enhancement