Since commit 37e015d4 (Utilities/Sphinx: Refactor Sphinx reference
recording, 2023-03-08, v3.27.0-rc1~342^2~1), anchors in links to cmake
domain objects generated in html search results were missing their
object type prefix, and thus did not link to the object.

Restore our `get_objects` implementation's second tuple entry to what we
used prior to that commit.  This matches what Sphinx's builtin python,
rst, and javascript modes do.

Fixes: #25067