Issue #2578559 by yched: Have ViewsSelection no longer extend SelectionBase

...rupal/Core/Entity/Annotation/EntityReferenceSelection.php

core/lib/Drupal/Core/Entity/Element/EntityAutocomplete.php

...re/Entity/EntityReferenceSelection/SelectionInterface.php

...ntity/EntityReferenceSelection/SelectionPluginManager.php

...Core/Entity/Plugin/Derivative/DefaultSelectionDeriver.php

...al/Core/Entity/Plugin/EntityReferenceSelection/Broken.php

...tity/Plugin/EntityReferenceSelection/DefaultSelection.php

...e/Entity/Plugin/EntityReferenceSelection/PhpSelection.php

.../Entity/Plugin/EntityReferenceSelection/SelectionBase.php

.../src/Plugin/EntityReferenceSelection/CommentSelection.php

...ile/src/Plugin/EntityReferenceSelection/FileSelection.php

...ode/src/Plugin/EntityReferenceSelection/NodeSelection.php

...omy/src/Plugin/EntityReferenceSelection/TermSelection.php

...ser/src/Plugin/EntityReferenceSelection/UserSelection.php

...ws/src/Plugin/EntityReferenceSelection/ViewsSelection.php