Fix missing name validation on object names at update (#5434)

## Context
as per title

## How was it tested? 
local (/metadata + in product)

packages/twenty-server/src/engine/metadata-modules/object-metadata/utils/__tests__/validate-object-metadata-input.util.spec.ts

@@ -0,0 +1,63 @@
+import { UpdateObjectPayload } from 'src/engine/metadata-modules/object-metadata/dtos/update-object.input';
+import { validateObjectMetadataInputOrThrow } from 'src/engine/metadata-modules/object-metadata/utils/validate-object-metadata-input.util';
+
+const validObjectInput: UpdateObjectPayload = {
+  labelPlural: 'Car',
+  labelSingular: 'Cars',
+  nameSingular: 'car',
+  namePlural: 'cars',
+};
+
+const reservedKeyword = 'user';
+
+describe('validateObjectName', () => {
+  it('should not throw if names are valid', () => {
+    expect(() =>
+      validateObjectMetadataInputOrThrow(validObjectInput),
+    ).not.toThrow();
+  });
+
+  it('should throw is nameSingular has invalid characters', () => {
+    const invalidObjectInput = {
+      ...validObjectInput,
+      nameSingular: 'μ',
+    };
+
+    expect(() =>
+      validateObjectMetadataInputOrThrow(invalidObjectInput),
+    ).toThrow();
+  });
+
+  it('should throw is namePlural has invalid characters', () => {
+    const invalidObjectInput = {
+      ...validObjectInput,
+      namePlural: 'μ',
+    };
+
+    expect(() =>
+      validateObjectMetadataInputOrThrow(invalidObjectInput),
+    ).toThrow();
+  });
+
+  it('should throw if nameSingular is a reserved keyword', async () => {
+    const invalidObjectInput = {
+      ...validObjectInput,
+      nameSingular: reservedKeyword,
+    };
+
+    expect(() =>
+      validateObjectMetadataInputOrThrow(invalidObjectInput),
+    ).toThrow();
+  });
+
+  it('should throw if namePlural is a reserved keyword', async () => {
+    const invalidObjectInput = {
+      ...validObjectInput,
+      namePlural: reservedKeyword,
+    };
+
+    expect(() =>
+      validateObjectMetadataInputOrThrow(invalidObjectInput),
+    ).toThrow();
+  });
+});

packages/twenty-server/src/engine/metadata-modules/object-metadata/utils/validate-object-metadata-input.util.ts

@@ -1,27 +1,70 @@
-import { BadRequestException } from '@nestjs/common';
+import { BadRequestException, ForbiddenException } from '@nestjs/common';
 
 import { InvalidStringException } from 'src/engine/metadata-modules/errors/InvalidStringException';
 import { CreateObjectInput } from 'src/engine/metadata-modules/object-metadata/dtos/create-object.input';
 import { UpdateObjectPayload } from 'src/engine/metadata-modules/object-metadata/dtos/update-object.input';
 import { validateMetadataName } from 'src/engine/metadata-modules/utils/validate-metadata-name.utils';
 
-export const validateObjectMetadataInput = <
+const coreObjectNames = [
+  'appToken',
+  'billingSubscription',
+  'billingSubscriptions',
+  'billingSubscriptionItem',
+  'billingSubscriptionItems',
+  'featureFlag',
+  'user',
+  'users',
+  'userWorkspace',
+  'userWorkspaces',
+  'workspace',
+  'workspaces',
+];
+
+const reservedKeywords = [
+  ...coreObjectNames,
+  'event',
+  'events',
+  'field',
+  'fields',
+  'link',
+  'links',
+  'currency',
+  'currencies',
+  'fullName',
+  'fullNames',
+  'address',
+  'addresses',
+];
+
+export const validateObjectMetadataInputOrThrow = <
   T extends UpdateObjectPayload | CreateObjectInput,
 >(
   objectMetadataInput: T,
 ): void => {
-  try {
-    if (objectMetadataInput.nameSingular) {
-      validateMetadataName(objectMetadataInput.nameSingular);
-    }
+  validateNameCharactersOrThrow(objectMetadataInput.nameSingular);
+  validateNameCharactersOrThrow(objectMetadataInput.namePlural);
 
-    if (objectMetadataInput.namePlural) {
-      validateMetadataName(objectMetadataInput.namePlural);
+  validateNameIsNotReservedKeywordOrThrow(objectMetadataInput.nameSingular);
+  validateNameIsNotReservedKeywordOrThrow(objectMetadataInput.namePlural);
+};
+
+const validateNameIsNotReservedKeywordOrThrow = (name?: string) => {
+  if (name) {
+    if (reservedKeywords.includes(name)) {
+      throw new ForbiddenException(`The name "${name}" is not available`);
+    }
+  }
+};
+
+const validateNameCharactersOrThrow = (name?: string) => {
+  try {
+    if (name) {
+      validateMetadataName(name);
     }
   } catch (error) {
     if (error instanceof InvalidStringException) {
       throw new BadRequestException(
-        `Characters used in name "${objectMetadataInput.nameSingular}" or "${objectMetadataInput.namePlural}" are not supported`,
+        `Characters used in name "${name}" are not supported`,
       );
     } else {
       throw error;