[zorg] Fix LLDBCmakeBuildFactory
The attempt in D69341 was not complete, as in the monorepo world, we
also need to pass LLVM_ENABLE_PROJECTS in order to build lldb (and
clang and lld).
This also updates the code to use the CmakeCommand class instead of the
Reviewers: jankratochvil, stella.stamenova, gkistanova
Differential Revision: https://reviews.llvm.org/D69555