Add local only cache to cache service and cache typeorm entity metadata (#16287)

## Problem

buildEntityMetadatas in GlobalWorkspaceOrmManager is computationally
expensive and was running on every executeInWorkspaceContext call. This
method uses
TypeORM's EntitySchemaTransformer and EntityMetadataBuilder to build
metadata for all workspace entities (30-50+ objects with many fields
each).

The resulting EntityMetadata[] is not serialisable which means it cannot
be cached in Redis because they contain:
- Circular references
- Functions/methods
- References to the DataSource instance

## Solution

Extended the workspace cache system to support local-only caching, then
created a cache provider for entityMetadatas.

## Implementation details
Updated @WorkspaceCache decorator (workspace-cache.decorator.ts)
- Added localOnly?: boolean option to skip Redis storage for
non-serializable data
Created WorkspaceEntityMetadatasCacheService
- Computes entity metadatas from DB to avoid race condition, this is
acceptable
Simplified GlobalWorkspaceOrmManager
- Now fetches entityMetadatas from cache instead of rebuilding on every
call
Updated Workspace migration runner - the only entry point where metadata
can change
- Now invalidate the new 'entityMetadata' local cache when
shouldIncrementMetadataGraphqlSchemaVersion is true (== field/object
mutations)

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

@@ -124,6 +124,7 @@ export class WorkspaceMigrationRunnerV2Service {
           'userWorkspaceRoleMap',
           'flatRoleTargetMaps',
           'apiKeyRoleMap',
+          'ORMEntityMetadatas',
           'flatRoleTargetByAgentIdMaps',
         ]),
       );