Improve build after nr lte merge
Allow all nr and lte execs build in one pass (build_oai --UE --nrUE --gNB --eNB ...) Remove remaining ENABLE_USE_MME macro usage in nr code Allow build mode selection (Release | RelWithDebInfo | MinSizeRel | Debug) with the -g switch of the build_oai script (described in build_oai help message) Cleanup config module source inclusion at build time: in CMakelist.txt, always use CONFIG_LIB, no direct source inclusion