Build stripe integration on backend side (#5246)

Adding stripe integration by making the server logic independent of the
input fields:
- query factories (remote server, foreign data wrapper, foreign table)
to loop on fields and values without hardcoding the names of the fields
- adding stripe input and type
- add the logic to handle static schema. Simply creating a big object to
store into the server

Additional work:
- rename username field to user. This is the input intended for postgres
user mapping and we now need a matching by name

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Co-authored-by: Thomas Trompette <thomast@twenty.com>

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

@@ -2,9 +2,9 @@ import { ObjectType, Field } from '@nestjs/graphql';
 
 import { IsOptional } from 'class-validator';
 
-@ObjectType('UserMappingOptionsUsername')
+@ObjectType('UserMappingOptionsUser')
 export class UserMappingOptionsDTO {
   @IsOptional()
   @Field(() => String, { nullable: true })
-  username: string;
+  user: string;
 }