Currently SkinMustache requires all skins to manage their own code for menu generation. In T253938 we created a Skin method for creating portlets with the correct ID and classes.
All skins replicate the same logic and historically this has led to inconsistencies in markup e.g. T259401 and notably Minerva.
As we move more production skins onto SkinMustache I'd like to see these patterns generalized.
Benefits:
* consistent labels (More #cactions dropdown is duplicated in Vector and Monobook)
* consistent ID and classes across all SkinMustache-based skins - namely Vector and Example
# Acceptance criteria
[x] Skins using SkinMustache can render the standard MediaWiki menus without requiring the overriding of SkinMustache::getTemplateData
[] The Vector skin is showcasing the capability