...that was apparently left by accident by
24c709655e "clang-tidy modernize-pass-by-value in
comphelper", thwarting the use of std::move here.
And clean up the declarations in the include file, too.
(I came across this code with an upcoming loplugin:constmove that flags
suspicious uses of std::move involving const-qualified types.)
Change-Id: I8178ad09bc4e7d4f57c5dfd9b0e2103e6d4fa72a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/142566
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>