[RNE Rewrite] Setup clangd and clang-tidy setup for non-3rd party c++ code

[msluszniak]

We need to setup clangd with strong compile flags to make it easier to improve code during the rewrite process. The first step is to research which compile flags we should use. Then setup clangd. As a follow up, we need to setup clang-tidy static checks as a first step to potential clang-tidy CI.