Support for "modern" CMake handling of installed SDK missing

Would it be please possible to add support for the "modern" CMake way of working with the installed[1] SDK, i.e.

- identify components (api headers, cxx headers, icd loader)
- provide *Targets.cmake and *Config.cmake file(s) for the components and
- expose targets for working within CMake with the imported SDK

Furthermore, I would have expected that the "make install" handles the installation of all sub-modules (i.e. especially the headers, at least api and cxx) as well. Thank you for considering this!

[1]OTOH, there is no mention in the README about `make install` so maybe this is intentional? Just a thought.

Start by reviewing the README and the current CMake and make install behavior for the installed SDK. Map the API headers, C++ headers, and ICD loader into components, then determine the required *Targets.cmake and *Config.cmake files and imported targets. Done means the SDK components and headers install correctly and can be consumed through modern CMake.

Written by the indexing model from the issue text.