Refactor object metadata service (#8123)

## Context
ObjectMetadataService became quite large and handles too many
responsibilities. I'm trying to refactor a bit this part in preparation
of a larger work that will combine object-metadata services and
sync-metadata logic

- Created a STANDARD_OBJECT_ICONS that can be reused in relation
creation to refer to a standard object icon.
- Created a STANDARD_OBJECT_FIELD_IDS that can be used with an object
name to get its standard field ids.
- Moved migration, record and relation creations to dedicated services,
refactored to improve performances and readability
- Refactored some validation logic

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/src/engine/workspace-manager/workspace-cleaner/crons/clean-inactive-workspace.job.ts

@@ -9,13 +9,13 @@ import {
 import { In, Repository } from 'typeorm';
 
 import { TypeORMService } from 'src/database/typeorm/typeorm.service';
-import { UserService } from 'src/engine/core-modules/user/services/user.service';
-import { Workspace } from 'src/engine/core-modules/workspace/workspace.entity';
 import { EmailService } from 'src/engine/core-modules/email/email.service';
 import { EnvironmentService } from 'src/engine/core-modules/environment/environment.service';
 import { Process } from 'src/engine/core-modules/message-queue/decorators/process.decorator';
 import { Processor } from 'src/engine/core-modules/message-queue/decorators/processor.decorator';
 import { MessageQueue } from 'src/engine/core-modules/message-queue/message-queue.constants';
+import { UserService } from 'src/engine/core-modules/user/services/user.service';
+import { Workspace } from 'src/engine/core-modules/workspace/workspace.entity';
 import { DataSourceEntity } from 'src/engine/metadata-modules/data-source/data-source.entity';
 import { DataSourceService } from 'src/engine/metadata-modules/data-source/data-source.service';
 import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';