Blender Git Loki

Geometry Nodes: don't log full fields when not necessary

Previously, the field on every socket was logged for later use. This had
two main negative consequences:
* Increased memory usage, because the fields may contain a lot of data
under some circumstances (e.g. a Ray Cast field contains the target geometry).
* Decreased performance, because anonymous attributes could not be
removed from geometry automatically, because there were still fields that
referenced them.

Now most fields are not logged anymore. Only those that are viewed by a
spreadsheet and constant fields. The required inputs of a field are still
logged in string form to keep socket inspection working.