[llvm] [llvm-debuginfo-analyzer] Remove `LVScope::Children` container (PR #144750)

[Carlos Alberto Enciso via llvm-commits]

CarlosAlbertoEnciso wrote:

The changes that introduce the `none : unsorted output` should be in a separated patch, as it is a general feature, independent of the `children` removal and associated with `LVObject::ID`.

https://github.com/llvm/llvm-project/pull/144750