Remove Favorite and FavoriteFolder from workspace schema (#19536)

## Summary

- Removes all workspace schema definitions for `Favorite` and
`FavoriteFolder` entities, which have been fully migrated to
`NavigationMenuItems`
- Deletes 26 standalone files including workspace entities, NestJS
modules, services, listeners, jobs, standard application builders (field
metadata, views, view fields, view field groups, indexes, page layouts),
mocks, and integration tests
- Cleans up ~40 modified files: removes `favorites` relation from 10
workspace entities and their field metadata utils, removes entries from
all builder maps, shared constants (`STANDARD_OBJECTS`,
`CoreObjectNameSingular`, `DEFAULT_RELATIONS_OBJECTS_STANDARD_IDS`), SDK
default relations, AI tool filtering, and standard object icons

packages/twenty-server/src/engine/metadata-modules/object-metadata/utils/build-default-relation-flat-field-metadatas-for-custom-object.util.ts

@@ -24,7 +24,6 @@ import { type UniversalFlatObjectMetadata } from 'src/engine/workspace-manager/w
 const morphIdByRelationObjectNameSingular = {
   timelineActivity:
     STANDARD_OBJECTS.timelineActivity.morphIds.targetMorphId.morphId,
-  favorite: null,
   attachment: STANDARD_OBJECTS.attachment.morphIds.targetMorphId.morphId,
   noteTarget: STANDARD_OBJECTS.noteTarget.morphIds.targetMorphId.morphId,
   taskTarget: STANDARD_OBJECTS.taskTarget.morphIds.targetMorphId.morphId,