Move view in metadata-modules/ and create atomic folder + module for each view entity (#14990)

# Introduction
Preparing view-filter and view-group introduction in v2 core engine
Moving view from `core-modules` to `metadata-modules`

## What happened

### Created dedicated modules for each view entity:
- ViewFieldModule
- ViewFilterModule
- ViewFilterGroupModule
- ViewGroupModule
- ViewSortModule

### Each module is now completely independent with its own:
- Controller
- Resolver
- Service
- Entity

### Created dedicated abstraction metadata module folder for:
- flat-view-field
- flat-view

### Dependencies 
- Eleminated circular dep on ViewModule to all others ones
- Granular import not importing the whole viewModule anymore everywhere


close https://github.com/twentyhq/core-team-issues/issues/1703

packages/twenty-server/src/engine/metadata-modules/view-group/exceptions/view-group.exception.ts

@@ -0,0 +1,61 @@
+import { t } from '@lingui/core/macro';
+import { assertUnreachable } from 'twenty-shared/utils';
+
+import { CustomException } from 'src/utils/custom-exception';
+
+export class ViewGroupException extends CustomException {
+  declare code: ViewGroupExceptionCode;
+  constructor(
+    message: string,
+    code: ViewGroupExceptionCode,
+    { userFriendlyMessage }: { userFriendlyMessage?: string } = {},
+  ) {
+    super(message, code, { userFriendlyMessage });
+  }
+}
+
+export enum ViewGroupExceptionCode {
+  VIEW_GROUP_NOT_FOUND = 'VIEW_GROUP_NOT_FOUND',
+  INVALID_VIEW_GROUP_DATA = 'INVALID_VIEW_GROUP_DATA',
+}
+
+export enum ViewGroupExceptionMessageKey {
+  WORKSPACE_ID_REQUIRED = 'WORKSPACE_ID_REQUIRED',
+  VIEW_ID_REQUIRED = 'VIEW_ID_REQUIRED',
+  VIEW_GROUP_NOT_FOUND = 'VIEW_GROUP_NOT_FOUND',
+  INVALID_VIEW_GROUP_DATA = 'INVALID_VIEW_GROUP_DATA',
+  FIELD_METADATA_ID_REQUIRED = 'FIELD_METADATA_ID_REQUIRED',
+}
+
+export const generateViewGroupExceptionMessage = (
+  key: ViewGroupExceptionMessageKey,
+  id?: string,
+) => {
+  switch (key) {
+    case ViewGroupExceptionMessageKey.WORKSPACE_ID_REQUIRED:
+      return 'WorkspaceId is required';
+    case ViewGroupExceptionMessageKey.VIEW_ID_REQUIRED:
+      return 'ViewId is required';
+    case ViewGroupExceptionMessageKey.VIEW_GROUP_NOT_FOUND:
+      return `View group${id ? ` (id: ${id})` : ''} not found`;
+    case ViewGroupExceptionMessageKey.INVALID_VIEW_GROUP_DATA:
+      return `Invalid view group data${id ? ` for view group id: ${id}` : ''}`;
+    case ViewGroupExceptionMessageKey.FIELD_METADATA_ID_REQUIRED:
+      return 'FieldMetadataId is required';
+    default:
+      assertUnreachable(key);
+  }
+};
+
+export const generateViewGroupUserFriendlyExceptionMessage = (
+  key: ViewGroupExceptionMessageKey,
+) => {
+  switch (key) {
+    case ViewGroupExceptionMessageKey.WORKSPACE_ID_REQUIRED:
+      return t`WorkspaceId is required to create a view group.`;
+    case ViewGroupExceptionMessageKey.VIEW_ID_REQUIRED:
+      return t`ViewId is required to create a view group.`;
+    case ViewGroupExceptionMessageKey.FIELD_METADATA_ID_REQUIRED:
+      return t`FieldMetadataId is required to create a view group.`;
+  }
+};