Handle `extras` option in `IntegerValidator`

[archmoj]

extras are added to plotly.js integer validator in https://github.com/plotly/plotly.js/pull/6990/commits/37dee4852e335067508add73de7ee7a59e8db045 i.e. to handle cases like bold and normal in font.weight which could also be a number between 1-1000.

This commit would be required in updating to upcoming plotly.js v2.33.0.

@LiamConnors cc: @emilykl @gvwilson