A Portal (or portlet) in the Vector context is a section of the
sidebar menu (e.g. Tools, Languges etc.).
The hook that places content between the portals (or portlets?)
such as `SkinTemplateToolboxEnd` and `otherlanguages` has been
enclosed inside of an output buffer so that any content it
produces can be passed to a template.
Bug: T239248, T240062
Change-Id: I882db161e5462cf88aa48c9cfd91448eb97a4a77
