Support Google Cloud Style Customization

Support for Cloud-based maps styling would be a very useful feature, at least for my use case. (See https://developers.google.com/maps/documentation/maps-static/cloud-customization). It allows styling customization through a web based no-code interface, and for us to roll out a selected style organization or project wide with a one simple parameter.

All it would require is handling a new argument: map_id, and a little error checking to prevent users from specifying both a styling with the current style parameter, and a map_id (Since they use two different systems and are not supported by Google).

I'd be happy to take a first stab at this.

Start by locating where the existing style parameter is accepted and validated, then trace how map arguments are passed to Google Maps Static API requests. Add support for map_id while rejecting its combination with the current styling option. Done means cloud-customized maps work through map_id and conflicting styling arguments produce a clear error.

Written by the indexing model from the issue text.