Drop support for vectorMenu, vectorTabs and
vectorMenuCheckbox, body, menu selectors in preference
for standard selectors.
This change will impact a large amount of user scripts/styles but should
not impact any gadgets.
These classes were kept around for user scripts and styles however are not
needed internally. As we transition to a more maintainable skin menu
system, it is time to lose these selectors even though this will cause
disruption.
Vector now will use the mw-portlet class rather than the vector-menu
class in its own CSS styling, however it keeps the other classes to
allow differentiation of the different types of menu.
Changes to test: Previously the tests assumed all portlets were empty
when checking the classes. This is very rare, so its better to check
the classes of non-empty portlets, so several tests are updated
accordingly to drop the emptyPortlet class.
Bug: T262092
Change-Id: I1824335eb47d613c2a4804ec1f1106c0f4c16101