Remove logic function layer (#17697)

## Remove logic function layer

Package.json and yarn.lock are now on the application entity, so the
logic function layer is no longer used except as a legacy source for the
1.17 backfill. This PR removes all layer usage outside of that migration
and keeps only the entity for backfill.

### Summary

- **Kept:** `LogicFunctionLayerEntity` and its table, only used by the
1.17 backfill command to read legacy layer data and backfill application
package files.
- **Removed:** All other layer logic: CRUD, cache, resolvers, services,
DTOs, and frontend types. Logic functions now depend only on the
application for package/dependency context.


### Why Dependencies instead of Source for package files

Package.json and yarn.lock are the application’s dependency set and are
stored under the application in **FileFolder.Dependencies**. The build
service and drivers now read them only from Dependencies; nothing is
written to Source for these files.

packages/twenty-server/src/engine/metadata-modules/logic-function/dtos/create-logic-function.input.ts

@@ -38,9 +38,6 @@ export class CreateLogicFunctionInput {
   @HideField()
   universalIdentifier?: string;
 
-  @HideField()
-  logicFunctionLayerId?: string;
-
   @Field(() => graphqlTypeJson, { nullable: true })
   @IsObject()
   @IsOptional()