Extend the cbuild to optionally call cbuild2cmake instead of cbuildgen

[brondani]

Introduce a command line option (e.g. --cmake or --cbuild2cmake) for instructing cbuild to optionally call cbuild2cmake.
For generating/updating CMakeLists: cbuild2cmake <solution>.cbuild-idx.yml
For configuring: cmake -G Ninja -S tmp -B tmp
For building all artifacts: cmake --build tmp
For building artifacts of a given context: cmake --build tmp --target <context>
For updating the compilation database: cmake --build tmp --target <context>-database