Adds proper argument information to span tree. Fixes #7107

https://github.com/enso-org/enso/assets/3919101/f7773412-5f0f-46c9-9848-2dc653aee882

# Important Notes
Nodes where the left operand (target) is missing still does not work, because the engine still does not send us any method pointer (perhaps due to its internal design).