Install CMake configuration files into ${CMAKE_INSTALL_LIBDIR}/cmake/draco

[topazus]

It may be more proper to install cmake config files into ${CMAKE_INSTALL_LIBDIR}/cmake/draco to follow the current pratice, which is adopted by CMake documentation example and many c++ libraries.

Ref: https://gitlab.kitware.com/cmake/cmake/-/merge_requests/8111 https://cmake.org/cmake/help/latest/module/CMakePackageConfigHelpers.html https://github.com/google/re2/blob/11073deb73b3d01018308863c0bcdfd0d51d3e70/CMakeLists.txt#L198-L204