Deprecate FieldMetadataInterface (#13264)

# Introduction

From the moment replaced the FieldMetadataInterface definition to:
```ts
import { FieldMetadataType } from 'twenty-shared/types';

import { FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';

export type FieldMetadataInterface<
  T extends FieldMetadataType = FieldMetadataType,
> = FieldMetadataEntity<T>;
```
After this PR merge will create a new one removing the type and
replacing it to `FieldMetadataEntity`.
Did not renamed it here to avoid conflicts on naming + type issues fixs
within the same PR

## Field metadata entity RELATION or MORPH
Relations fields cannot be null for those field metadata entity instance
anymore, but are never for the others see
`packages/twenty-server/src/engine/metadata-modules/field-metadata/types/field-metadata-entity-test.type.ts`
( introduced TypeScript tests )

## Concerns
- TS_VECTOR is the most at risk with the `generatedType` and
`asExpression` removal from interface

## What's next
- `FielMetadataInterface` removal and rename ( see introduction )
- Depcrecating `ObjectMetadataInterface`
- Refactor `FieldMetadataEntity` optional fiels to be nullable only
- TO DIG `never` occurences on settings, defaultValue etc
- Some interfaces will be replaced by the `FlatFieldMetadata` when
deprecating the current sync and comparators tools

packages/twenty-server/src/utils/__test__/get-field-metadata-entity.mock.ts

@@ -0,0 +1,47 @@
+import { faker } from '@faker-js/faker';
+import { FieldMetadataType } from 'twenty-shared/types';
+
+import { FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';
+import { IndexFieldMetadataEntity } from 'src/engine/metadata-modules/index-metadata/index-field-metadata.entity';
+import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
+
+type GetMockFieldMetadataEntityOverride<
+  T extends FieldMetadataType = FieldMetadataType,
+> = Partial<FieldMetadataEntity<T>> &
+  Required<Pick<FieldMetadataEntity<T>, 'workspaceId' | 'objectMetadataId'>>;
+
+export const getMockFieldMetadataEntity = <
+  T extends FieldMetadataType = FieldMetadataType.TEXT,
+>(
+  overrides: GetMockFieldMetadataEntityOverride<T>,
+): FieldMetadataEntity<T> => {
+  return {
+    type: FieldMetadataType.TEXT as T,
+    fieldPermissions: [],
+    icon: null,
+    indexFieldMetadatas: {} as IndexFieldMetadataEntity,
+    isCustom: true,
+    isLabelSyncedWithName: false,
+    isNullable: null,
+    isSystem: false,
+    isUnique: null,
+    object: {} as ObjectMetadataEntity,
+    relationTargetFieldMetadata: null as never,
+    relationTargetFieldMetadataId: null as never,
+    relationTargetObjectMetadata: null as never,
+    relationTargetObjectMetadataId: null as never,
+    standardId: null,
+    standardOverrides: null,
+    id: faker.string.uuid(),
+    name: 'defaultFieldMetadataName',
+    label: 'Default field metadata entity label',
+    description: 'Default field metadata entity description',
+    defaultValue: null,
+    options: null,
+    settings: null,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    isActive: true,
+    ...overrides,
+  };
+};