Revert "Implemented List_setField(id, i, j, field, value)"

This reverts commit 7fc8443ead212b2ebd52c96f73185d19bc3c6dd0.
Revert "Generalized List_getItemField to List_getItem"

This reverts commit ed8af916cbfd0dc15d92144ccb5ffcda69956b76.