add validation option to style setters

[mollymerp]

Launch Checklist

• briefly describe the changes in this PR
• write tests for all new functionality
• document any changes to public APIs
• manually test the debug page
• tagged @mapbox/studio and/or @mapbox/maps-design if this PR includes style spec changes

[mourner]

This looks great! The only nit: should we cut out the {validate?: boolean} part into a common ValidateOptions type so that we don't repeat it everywhere? Or maybe something like StylingOptions if we plan to add some non-validation-related options.

[clement-igonet]

Where can I see "option.validate" documentation nowdays ?
I do not see any reference here: https://docs.mapbox.com/mapbox-gl-js/style-spec/

[ryanhamley]

@clement-igonet This option is for certain setters such as setFilter and the documentation is at the individual method docs, e.g. https://docs.mapbox.com/mapbox-gl-js/api/#map#setfilter