Optimize EntityMetadata caching in GlobalWorkspaceDataSource (#16146)

## Context
EntityMetadata was being rebuilt from scratch on every
findMetadata()/getMetadata() call (~20 times per request). This involved
running EntitySchemaTransformer.transform() and
EntityMetadataBuilder.build() repeatedly, causing unnecessary CPU
overhead.

## Implementation
Cache entityMetadatas in ORMWorkspaceContext: Build EntityMetadata once
during workspace context initialization instead of on every metadata
lookup
Remove redundant entitySchemas caching: Since flatMetadata is already
cached, the additional Redis cache for entitySchemaOptions was
unnecessary overhead
Remove WorkspaceEntitiesStorage: Replaced with direct lookup from
FlatObjectMetadataMap
Simplify getObjectMetadataFromEntityTarget: Now only accepts string
targets, using flat metadata maps directly

Also:
Removed unused injections in some services

packages/twenty-server/src/modules/messaging/message-import-manager/services/messaging-process-group-email-actions.service.ts

@@ -4,7 +4,6 @@ import { isDefined } from 'twenty-shared/utils';
 
 import { type WorkspaceEntityManager } from 'src/engine/twenty-orm/entity-manager/workspace-entity-manager';
 import { TwentyORMManager } from 'src/engine/twenty-orm/twenty-orm.manager';
-import { MessageChannelSyncStatusService } from 'src/modules/messaging/common/services/message-channel-sync-status.service';
 import {
   MessageChannelPendingGroupEmailsAction,
   MessageChannelWorkspaceEntity,
@@ -22,7 +21,6 @@ export class MessagingProcessGroupEmailActionsService {
     private readonly twentyORMManager: TwentyORMManager,
     private readonly messagingDeleteGroupEmailMessagesService: MessagingDeleteGroupEmailMessagesService,
     private readonly messagingClearCursorsService: MessagingClearCursorsService,
-    private readonly messageChannelSyncStatusService: MessageChannelSyncStatusService,
   ) {}
 
   async markMessageChannelAsPendingGroupEmailsAction(

packages/twenty-server/src/modules/messaging/monitoring/services/messaging-monitoring.service.ts

@@ -1,7 +1,5 @@
 import { Injectable } from '@nestjs/common';
 
-import { AuditService } from 'src/engine/core-modules/audit/services/audit.service';
-
 type MessagingMonitoringTrackInput = {
   eventName: string;
   workspaceId?: string;
@@ -13,7 +11,7 @@ type MessagingMonitoringTrackInput = {
 
 @Injectable()
 export class MessagingMonitoringService {
-  constructor(private readonly _auditService: AuditService) {}
+  constructor() {}
 
   public async track({
     eventName: _eventName,