Issue #1976158 by Berdir | msonnabaum: Rename entity storage/list/form/render "controllers" to handlers.

Issue #2154435 by andypost, Berdir, mparker17: Rename EntityAccessController to EntityAccessControlHandler.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #1709960 by Berdir, zserno, jessebeach | joachim: Declare a maximum length for entity and bundle machine names.

Issue #2120871 by andypost, Berdir, amateescu, vladan.me, Xano: Rename EntityListController to EntityListBuilder.

Issue #2168333 by tim.plunkett, EclipseGc, yched, fago: Ensure custom EntityType controllers can be provided by modules.

Issue #2005716 by tim.plunkett, msonnabaum, dawehner, alexpott, effulgentsia: Promote EntityType to a domain object.