fix: #3548600 by andres-alvarez: consolidate entity links into display_builder_ui hook

All UI routes for pattern_preset, display_builder_profile and display_builder_instance are managed by display_builder_ui.routing.yml, yet link templates were split between entity annotations (main modules) and the routing file. Moved all nine link templates to DisplayBuilderUiHooks::entityTypeAlter() for single source of truth. Added kernel test confirming links resolve correctly via hook. Kept edit-plugin-form on profile entity since that route is not managed by display_builder_ui.