Add warning for Chrome

[oeway]

We need to check if it's a chromium compatible browser for the colab tool, here is the code to check it:

if (!window.showOpenFilePicker) {}

We should show a (yellow) warning message box if not supported, here is a warning message example: https://github.com/bioimage-io/bioimageio-chatbot/blob/69393e77d9a14496c96704b25eac535d15ad9aab/bioimageio_chatbot/static/index.html#L922

@nilsmechtel could you implement this?