Debounce updates from component

[resivalex]

Hi, @asg017. Your package is amazing!

I noticed a problem with frequent updates. Streamlit reloads a whole page and resets its state. You can see it also in your demonstration, just move a slider continuously for several seconds. I found out that the problem isn't connected with streamlit-observable and it also exists in the latest version of Streamlit.

I suggest adding an option for debouncing frequent updates. I'll return with pull request soon.