Feature/support multi tenant chat

[niztal]

In continuous to the conversation upon https://github.com/FlowiseAI/Flowise/pull/1709 I've added the support of multi tenant chatId with concatenation of {customerId}_{chatId}.

This way while singe chatflow serves multiple tenants, we can still have grouping of chat messages by specific customer (later on also chat messages feedbacks) by querying all the rows which contains in the chatId column the required customer's id.

@chungyau97 @HenryHengZJ please review

Thanks

[niztal]

@HenryHengZJ can you please review?

[niztal]

@HenryHengZJ I've fixed all of your comments, please review

Thanks

[HenryHengZJ]

thanks @niztal !