Fix flatFieldMetadata transpiler to fit real cache typing (#13529)

# Introduction
The cache is not accurately typed regarding the `fieldMetadataMaps` they
do not contain relations
In this way we:
- Created dedicated transpilation tools for cache manipulation
- Avoided recursivity in transpilation tools
- Fix and finalized the createMany fields metadata service v2
- Refactor the validator to handle validation :)

## What's next:
- Implem integration tests to make things run 🙃 
- migrate existing settings valdiation
- Finish the create object metadata service
- Handle update input transpilation and validation

packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/utils/from-object-metadata-entity-to-flat-object-metadata-without-fields.util.ts

@@ -0,0 +1,12 @@
+import { FlatObjectMetadataWithoutFields } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata.type';
+import { fromObjectMetadataEntityToFlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/utils/from-object-metadata-entity-to-flat-object-metadata.util';
+import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
+
+export const fromObjectMetadataEntityToFlatObjectMetadataWithoutFields = (
+  objectMetadataEntity: ObjectMetadataEntity,
+): FlatObjectMetadataWithoutFields => {
+  return fromObjectMetadataEntityToFlatObjectMetadata({
+    ...objectMetadataEntity,
+    fields: [],
+  });
+};

packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/workspace-migration-builder-v2.service.ts

@@ -36,6 +36,7 @@ export class WorkspaceMigrationBuilderV2Service {
         createdObjectMetadata,
         deletedObjectMetadata,
         updatedObjectMetadata,
+        inferDeletionFromMissingObjectFieldIndex,
       });
 
     const createdObjectMetadataCreateIndexActions =

packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/workspace-migration-v2-object-actions-builder.ts

@@ -13,11 +13,14 @@ import {
 } from 'src/engine/workspace-manager/workspace-migration-v2/workspace-migration-builder-v2/utils/get-workspace-migration-v2-object-actions';
 
 export type CreatedDeletedUpdatedObjectMetadataInputMatrix =
-  CustomDeletedCreatedUpdatedMatrix<'objectMetadata', FlatObjectMetadata>;
+  CustomDeletedCreatedUpdatedMatrix<'objectMetadata', FlatObjectMetadata> & {
+    inferDeletionFromMissingObjectFieldIndex: boolean;
+  };
 export const buildWorkspaceMigrationV2ObjectActions = ({
   createdObjectMetadata,
   deletedObjectMetadata,
   updatedObjectMetadata,
+  inferDeletionFromMissingObjectFieldIndex,
 }: CreatedDeletedUpdatedObjectMetadataInputMatrix): WorkspaceMigrationObjectActionV2[] => {
   const createdObjectActions = createdObjectMetadata.map(
     (flatObjectMetadata) => {
@@ -36,9 +39,9 @@ export const buildWorkspaceMigrationV2ObjectActions = ({
     },
   );
 
-  const deletedObjectActions = deletedObjectMetadata.map(
-    getWorkspaceMigrationV2ObjectDeleteAction,
-  );
+  const deletedObjectActions = inferDeletionFromMissingObjectFieldIndex
+    ? deletedObjectMetadata.map(getWorkspaceMigrationV2ObjectDeleteAction)
+    : [];
 
   const updatedObjectActions =
     updatedObjectMetadata.flatMap<UpdateObjectAction>(({ from, to }) => {