ApiQuerySiteinfo: Use proper localised skin display names if available

Based on the code in Preferences::generateSkinOptions(). This should
probably be turned into a helper method one day…

Bug: 48953
Change-Id: Ib85a783bd19de8a59e7b81a4203a05b786e67772
Merge "ApiQuerySiteinfo: Use proper localised skin display names if available"