Feature/Add message history to agents

[HenryHengZJ]

Adding few shot messages can greatly increase model performance, especially when it comes to function calling.

Reference: https://blog.langchain.dev/few-shot-prompting-to-improve-tool-calling-performance/

[jazzandrock]

Hi guys! I was playing with your example called "Advanced Structured Output Parser" from the Marketplaces tab, and it didn't work. I think it's because of this line from this PR:

if ((messageHistory && messageHistory === 'messageHistoryCode') || (selectedTab === 'messageHistoryCode' && messageHistoryCode)) {

Where messageHistoryCode can be undefined.

With this line modified to check for messageHistoryCode, the example works. Maybe this is a bug.

Anyway, thank you for the amazing product!

[HenryHengZJ]

Hey @jazzandrock thanks for the heads-up! Would you be able to submit a PR fix? Happy to accept!