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/test/integration/metadata/suites/field-metadata/enum/create-one-field-metadata-enum.integration-spec.ts

@@ -71,7 +71,7 @@ describe.each(fieldMetadataEnumTypes)(
         expect(data.createOneField.type).toEqual(testedFieldMetadataType);
 
         const createdOptions = data.createOneField.options;
-        const optionsToCompare = expectedOptions ?? input.options;
+        const optionsToCompare = expectedOptions ?? input.options ?? [];
 
         expect(errors).toBeUndefined();
         expect(createdOptions?.length).toBe(optionsToCompare.length);

packages/twenty-server/test/integration/metadata/suites/field-metadata/enum/update-one-enum-field-metadata.integration-spec.ts

@@ -168,12 +168,19 @@ describe.each(fieldMetadataEnumTypes)(
         expect(data.updateOneField).toBeDefined();
         const updatedOptions:
           | FieldMetadataComplexOption[]
-          | FieldMetadataDefaultOption[] = data.updateOneField.options;
+          | FieldMetadataDefaultOption[]
+          | null = data.updateOneField.options;
+
+        expect(updatedOptions).toBeDefined();
+        if (!isDefined(updatedOptions))
+          throw new Error(
+            'Should never occur, type invariant post test assertion',
+          );
 
         expect(errors).toBeUndefined();
         updatedOptions.forEach((option) => expect(option.id).toBeDefined());
 
-        const optionsToCompare = expectedOptions ?? input.options;
+        const optionsToCompare = expectedOptions ?? input.options ?? [];
 
         expect(updatedOptions.length).toBe(optionsToCompare.length);
         expect(updatedOptions).toMatchObject(optionsToCompare);