full cmake 3/N: orderings and configuration passing

[loriab]

currently atop #309 . here's the diff of the new stuff: https://github.com/loriab/libint/compare/intconfig...loriab:libint:orderingsconfig

• [x] handle the 3 orderings options with CMake and add history and upgrade helper entries
• [x] make sure version info, soversion info integral types/am/deriv components, orderings get passed through to libint2-config.cmake, config.h, configuration.cc, features
• [x] add skeleton of the full cmake structure: generate->export->library. No source files compiled yet, but options are handed through and configure_files are in place. rm -rf build/ && cmake -S. -Bbuild && cmake --build build completes so libint2-config.cmake and other files in previous bullet can be inspected
• configuration.cc (for libtool) and configuration.cc.cmake.in (for cmake) are duplicated at the moment