Add kokkos build to cmake

[greole]

This PR includes kokkos into our build system if no preinstalled kokkos was found.

Our build system will search for kokkos and if it isn't present, clone and build as part of the build process. To do this we use FetchContent_Declare which treats kokkos as subproject. While being quite flexible this will make Kokkos options visible in ccmake. In any case, the preferred way is to use a system wide installation of Kokkos and depend on find_package(Kokkos)

Additional

• static and sanitizer checks have been fixed
• use vanilla clang-format for the github format check action

[HenningScheufler]

lower cmake standard to: cmake_minimum_required(VERSION 3.22.0)