[FEATURE] Support customized conversation name/title for new conversation

[Hailong-am]

Is your feature request related to a problem?

For now when start a new conversation, the title/name of this new conversation is user question by default. we would like to support user defined name when start the new conversation.

What solution would you like?

Add a new parameter like conversation_name and use this as default conversation name, if this is not provided we can fallback to user question.

What alternatives have you considered?

1. use update conversation api to update conversation name after first interaction of this conversation
2. create a conversation manually first and reuse the conversation id

Do you have any additional context? Add any other context or screenshots about the feature request here.