plugin.Responsive: remove Neo.Responsive

without doing a deep dive, using Neo.Responsive feels like a namespace pollution.

in case we want to share data across all instances of the plugin, we can either use a static class field or define a variable inside the module (e.g. on top of the class definition).

it kind of depends if we want to provide access to the data outside of the plugin. but even if so, we should expose a getter method inside the plugin to do this.