To complete the refactor, the Portal is also refactored
as a Menu using the getMenu function.
An old code path supporting portals outputted by hooks with
strings is marked as deprecated to simplify this code in future.
array-portals-first -> data-portals-first (the value is not
an array)
Changes:
* $this->getLanguages and $this->getToolbox() always returns an array (see BaseTemplate)
but we previously supported portals made using raw HTML. Let's move away from that
behaviour and deprecate it.
* Hooks are moved into buildSidebarProps and marked as deprecated where possible
(SkinTemplateToolboxEnd). SidebarBeforeOutput can be used instead.
Bug: T249372
Change-Id: I2549af3e24e5d51c09e9a88ca50a0d9b2e154c3f
