No other access in the Title class contains a `get` prefix, so this
makes the title methods consistent.
Bug: T373047
Change-Id: I4a3a7498462b7b3b6143dc61f529e526ccb112e2
In order to avoid misleading the caller, set some title properties to
nil for interwiki links. That value should still be falsey, but can
prevent making unwarranted assumptions about the destination of
interwiki links.
Split from I847ac4b7587b98be06b25fe14765e9efdc7b774d because this
could possibly have effects on existing modules.
Change-Id: I06efea9b264ba0f09bfb36e6bf1bb04f1cdd03e4