The main goal here is to add `GeoTreeLogger.tree_orig_session_uid`. Previously,
it was always possible to derive this information in `ensure_node_warnings`.
However, with closures that's not possible in general anymore, because the
Evaluate Closure node does not know statically which node tree the closure zone
is from that it evaluates. Therefore, this information has to be logged as well.
This patch initializes `tree_orig_session_uid` the same way it initializes
`parent_node_id`, by scanning the compute context when creating the tree logger.
To make this work properly, some extra contextual data had to be stored in some
compute contexts.
This is just a refactor with no expected functional changes. Node warnings for
closures are still not properly logged, because that requires storing
source-location data in closures, which will be implemented separately.
Pull Request: https://projects.blender.org/blender/blender/pulls/137208
dcc8d28859