PHPCS Fixes for admin mod_menu

Adds in some fixes for the PHPCS issues in the admin mod menu component found in @mbabker 's thing here http://mbabker.github.io/jcms-codestyle/reports/administrator/modules.xml

Not everything is fixed (just by far the majority) as there are some doc comments I've left out as I'm too tired right now to work out what some of the longer functions actually do :)

No code changes made.