[clang] [analyzer] Use makeNode instead of ExplodedGraph::getNode (PR #218462)

[Balázs Benics via cfe-commits]

https://github.com/steakhal approved this pull request.

LGTM. Are there any other uses of `G.getNode`?
I figure your comment universally apply and we should gradually migrate away from `G.getNode`

https://github.com/llvm/llvm-project/pull/218462