Rename types for UserMappingOptions (#5230)

Following #5210

---------

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

packages/twenty-server/src/engine/metadata-modules/remote-server/dtos/user-mapping-dto.ts

@@ -0,0 +1,10 @@
+import { ObjectType, Field } from '@nestjs/graphql';
+
+import { IsOptional } from 'class-validator';
+
+@ObjectType('UserMappingOptionsUsername')
+export class UserMappingOptionsDTO {
+  @IsOptional()
+  @Field(() => String, { nullable: true })
+  username: string;
+}