(apply) Convert function applications to higher order variable instances, then adjust operator structure:
| 1. | If it's a var, its name will become the opid. |
| 2. | If it's blank, the (current_object ()) will become the opid. |
| 3. | Edit slots will be eliminated. |
| 4. | The bindings are adjusted to match the arities of the var instances in their scope. |