We already have a command to generate a new controller. But sometimes you have to add a new action to an existing controller.

The command would ask whether one wants to create a blank page, a page with top menu and logo (extends dashboard.twig) or admin page (extends admin.twig).

Note: There is already a method to copy a method from a template to an existing class https://github.com/piwik/piwik/blob/2.6.1/plugins/CoreConsole/Commands/GeneratePluginBase.php#L124