A CMake-based build and configuration framework

<!--HTML-->The LHCb experiment has been using the CMT build and configuration tool for its software since the first versions, mainly because of its multi-platform build support and its powerful configuration management functionality. Still, CMT has some limitations in terms of build performance and the increased complexity added to the tool to cope with new use cases added latterly. Therefore, we have been looking for a viable alternative to it and we have investigated the possibility of adopting the CMake tool, which does a very good job for building and is getting very popular in the HEP community. The result of this study is a CMake-based framework which provides most of the special configuration features available natively only in CMT, with the advantages of better performances, flexibility and portability.