Refactor flat entity maps to be universal oriented (#17665)

# Introduction
In preparation of the workspace agnostic builder, we're migrating
`FlatEntityMaps` to be universal identifier oriented and based
As in the builder context there're won't be any ids at all
Please also note that the FlatEntity is a UniversalFlatEntity superset

From
```ts
import { type SyncableFlatEntity } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-from.type';

export type FlatEntityMaps<T extends SyncableFlatEntity> = {
  byId: Partial<Record<string, T>>;
  idByUniversalIdentifier: Partial<Record<string, string>>;
  universalIdentifiersByApplicationId: Partial<Record<string, string[]>>;
};
```

To
```ts
export type FlatEntityMaps<
  T extends SyncableFlatEntity | UniversalSyncableFlatEntity,
> = {
  byUniversalIdentifier: Partial<Record<string, T>>;
  universalIdentifierById: Partial<Record<string, string>>;
  universalIdentifiersByApplicationId: Partial<Record<string, string[]>>; // this might make more sense to be migrated to universalIdentifiersByApplicationUniversalIdentifier but it's the main topic of this PR
};
```

## Low level maps tools
Had to refactor find | create | delete | replace | find-many | get-sub
tools ( through mutations and or throw equivalent )

packages/twenty-server/src/engine/metadata-modules/flat-view/utils/from-delete-view-input-to-flat-view-or-throw.util.ts

@@ -5,6 +5,7 @@ import {
 } from 'twenty-shared/utils';
 
 import { type FlatViewMaps } from 'src/engine/metadata-modules/flat-view/types/flat-view-maps.type';
+import { findFlatEntityByIdInFlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/utils/find-flat-entity-by-id-in-flat-entity-maps.util';
 import { type FlatView } from 'src/engine/metadata-modules/flat-view/types/flat-view.type';
 import { type DeleteViewInput } from 'src/engine/metadata-modules/view/dtos/inputs/delete-view.input';
 import {
@@ -24,7 +25,10 @@ export const fromDeleteViewInputToFlatViewOrThrow = ({
     ['id'],
   );
 
-  const existingFlatViewToDelete = flatViewMaps.byId[viewId];
+  const existingFlatViewToDelete = findFlatEntityByIdInFlatEntityMaps({
+    flatEntityId: viewId,
+    flatEntityMaps: flatViewMaps,
+  });
 
   if (!isDefined(existingFlatViewToDelete)) {
     throw new ViewException(

packages/twenty-server/src/engine/metadata-modules/flat-view/utils/from-destroy-view-input-to-flat-view-or-throw.util.ts

@@ -5,6 +5,7 @@ import {
 } from 'twenty-shared/utils';
 
 import { type FlatViewMaps } from 'src/engine/metadata-modules/flat-view/types/flat-view-maps.type';
+import { findFlatEntityByIdInFlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/utils/find-flat-entity-by-id-in-flat-entity-maps.util';
 import { type FlatView } from 'src/engine/metadata-modules/flat-view/types/flat-view.type';
 import { type DestroyViewInput } from 'src/engine/metadata-modules/view/dtos/inputs/destroy-view.input';
 import {
@@ -24,7 +25,10 @@ export const fromDestroyViewInputToFlatViewOrThrow = ({
     ['id'],
   );
 
-  const existingFlatViewToDestroy = flatViewMaps.byId[viewId];
+  const existingFlatViewToDestroy = findFlatEntityByIdInFlatEntityMaps({
+    flatEntityId: viewId,
+    flatEntityMaps: flatViewMaps,
+  });
 
   if (!isDefined(existingFlatViewToDestroy)) {
     throw new ViewException(

packages/twenty-server/src/engine/metadata-modules/flat-view/utils/from-update-view-input-to-flat-view-to-update-or-throw.util.ts

@@ -6,6 +6,7 @@ import {
 } from 'twenty-shared/utils';
 
 import { type FlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-maps.type';
+import { findFlatEntityByIdInFlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/utils/find-flat-entity-by-id-in-flat-entity-maps.util';
 import { type FlatFieldMetadata } from 'src/engine/metadata-modules/flat-field-metadata/types/flat-field-metadata.type';
 import { type FlatViewGroupMaps } from 'src/engine/metadata-modules/flat-view-group/types/flat-view-group-maps.type';
 import { type FlatViewGroup } from 'src/engine/metadata-modules/flat-view-group/types/flat-view-group.type';
@@ -43,7 +44,10 @@ export const fromUpdateViewInputToFlatViewToUpdateOrThrow = ({
       ['id'],
     );
 
-  const existingFlatViewToUpdate = flatViewMaps.byId[viewToUpdateId];
+  const existingFlatViewToUpdate = findFlatEntityByIdInFlatEntityMaps({
+    flatEntityId: viewToUpdateId,
+    flatEntityMaps: flatViewMaps,
+  });
 
   if (!isDefined(existingFlatViewToUpdate)) {
     throw new ViewException(