Add `apply_chat_template` functionality

[Liyan06]

Hi, I realize that there is no apply_chat_template implemented for InternVL, which makes it not easy to integrate it into the code base with other models having apply_chat_template defined. Are you planning to add the apply_chat_template function to InternVL? Thanks!

[czczup]

Thank you for your suggestion. We will implement the apply_chat_template function in the next few days.