Add "security" as nav-item to project sidebar
Add "security" as nav-item to project sidebar

Moves the security dashboard and dependency list into it's own
top-level navigation item named 'Securty & Compliance', within the
project's sidebar.

This should only affect EE, since the template changes only touch
partials that get conditionally rendered and only exist in EE.

mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq