Migrate agent v2 (#16214)

# Introduction
Closes https://github.com/twentyhq/core-team-issues/issues/1980

In this PR we migrate the agent from v1 to v2.

## New FlatRoleTargetByAgentIdMaps
Derivated the `flatRoleTargetMaps` to be building a
`flatRoleTargetByAgentIdMaps` to ease retrieving a roleId to associate
to an agent

## Coverage
Added strong coverage on both failing and successful CRU agents
operations

---------

Co-authored-by: Weiko <corentin@twenty.com>

packages/twenty-server/src/engine/api/rest/core/rest-api-core.module.ts

@@ -32,7 +32,6 @@ import { UserRoleModule } from 'src/engine/metadata-modules/user-role/user-role.
 import { TwentyORMModule } from 'src/engine/twenty-orm/twenty-orm.module';
 import { WorkspaceCacheStorageModule } from 'src/engine/workspace-cache-storage/workspace-cache-storage.module';
 import { WorkspaceCacheModule } from 'src/engine/workspace-cache/workspace-cache.module';
-import { WorkspaceFlatMapCacheModule } from 'src/engine/workspace-flat-map-cache/workspace-flat-map-cache.module';
 
 const restApiCoreResolvers = [
   RestApiCreateOneHandler,
@@ -63,7 +62,6 @@ const restApiCoreResolvers = [
     TwentyORMModule,
     RecordTransformerModule,
     WorkspaceManyOrAllFlatEntityMapsCacheModule,
-    WorkspaceFlatMapCacheModule,
     ActorModule,
     FeatureFlagModule,
     CoreCommonApiModule,