Issue #1877632 by fago, jhodgdon: Improve comments and clean-up code for EntityNG and the TypedData API.

Issue #1874300 by Berdir, swentel: Remove $entity_type argument from field.module functions that receive a single $entity.

Issue #1869250 by fago, Berdir, das-peter, YesCT, mradcliffe, fubhy: Various EntityNG and TypedData API improvements.

Issue #1852966 by yched, Stalski, zuuperman, swentel: Rework entity display settings around EntityDisplay config entity.

Revert "Issue #1852966 by yched, swentel: Rework entity display settings around EntityDisplay config entity."

This reverts commit 8ad67af2.

Issue #1852966 by yched, swentel: Rework entity display settings around EntityDisplay config entity.