Windows: use the basename of the product (.dll) for definition files

Windows: use the basename of the product (.dll) for definition files

This resolves the faulty LIBRARY value that contained the directory
of the product (.dll) in the build tree.  This applies to engines and
other modules alike.

Fixes #18726

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/18732)