Fix the UX of Entity Reference fields [#2116551]

Problem/Motivation [#1757452] added config entities back into the selection here, after this was deliberately taken out in [#1801304] taken out of the UI since the initial ER pach didn't support config entities. This leads to completely silly lists of possible things to reference like this: Here you have your "90% case" stuff (Content, Users, Files, etc.) buried hopelessly in amongst a bunch of "1% or less case" stuff like "Editor" and "Text format" and "Breakpoint group." This needs to be fixed, because it makes what's already a challenging field to use about 600x more difficult.

Inspect the configured ER component to prevent runtime issues

Custom Action Invalid Argument Error : Entity Reference cannot

Add Entity reference fields like: User reference, Content

Libero Config Get File - Colaboratory

Prioritize 'add existing' in nested entity creation UX to prevent

Keyword-based faceted search interface for knowledge graph

EVA and Entity Reference Use Case How-to

Add Entity reference field [#1801304]

Views Filter by an entity reference view not working as expected

Libero Config Get File - Colaboratory

8 - View for Entity Reference reverse, backwards forwards - Drupal

How to Enforce Selection of Published Contents in Entity Reference

no unique index found for the referenced field of a primary table