Issue #3623911: Decide which entity types are worth an endpoint before...

Issue #3623911: Decide which entity types are worth an endpoint before planning one for every bundle

The scanner records which entity types a reader of the site has a page for: a canonical link template whose route is not an administration route, or, before the router is built, whose path is not under /admin. The planner applies the detail and listing rules only to those types, so orders, payments, blocks, menu links, path aliases and the like are no longer planned by default. The new myrest_scaffold.settings:planned_entity_types setting plans any other type with "include", recorded in the plan as the site's decision, and leaves out a default one with "exclude".

Closes #3623911