[FEATURE] Improve CMake support

[Davide-1998]

Hi, great project 💪🏻
It would be awesome if it had a root CMakeLists.txt exposing hdds by both calling cargo and exposing the generated libraries as imported targets.
Maybe even a CMake function able to call the hddsgen that allows generating compiled IDL files at building-time

[hdds-team]

Thanks, and great suggestion 💪 - first-class CMake support makes a lot of sense given HDDS already ships C and C++ SDKs. The shape you describe is right on: a root CMakeLists.txt that drives the cargo build, exposes the C/C++ libraries as imported targets, and a helper function (e.g. hdds_generate_idl()) that runs the code generator at build time.

This is a well-scoped, additive piece that wouldn't touch the core - an ideal contribution if you're up for it (see CONTRIBUTING.md, DCO sign-off, Apache-2.0 OR MIT). Happy to help scope it and review. Marking as help wanted.