[DF] Fix Snapshot of aliased custom columns
[DF] Fix Snapshot of aliased custom columns

Fixes ROOT-9452

olifre/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,karies/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,karies/root,karies/root,root-mirror/root,olifre/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,karies/root,olifre/root,karies/root,olifre/root,karies/root,olifre/root,karies/root