[Guided Setup] : Speed up default tree creation

[alesan99]

Describe the bug
Tree creation takes a really long time, tree records should be batched.
#6429

Once this is working, we need to allow users to populate the tree upon creating the discipline (both in guided setup and in the system config tool).

To Reproduce
Try #6429

Expected behavior
Tree creation should be relatively fast. Slow download speeds are expected, but import speeds can drastically be improved.