The forwarding of LinkTarget subclass functions to LinkTarget functions
is currently done in a very elegant way that only requires listing the
bare function names once, but the downside is that the subclass
functions aren't defined in a way that "git grep" or "ctags" can find,
so replace that with more verbose copy-paste definitions.

Change-Id: I4bd7f1b1bc0904ae345958e39403ab508db584a1
Reviewed-on: https://gerrit.libreoffice.org/43196Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>