6181 workflows create a custom code executor (#6235)

Closes #6181

## Testing
- download Altair graphql dev tool https://altairgraphql.dev/#download
- create a file locally `test.ts` containing:
```
export const handler = async (event: object, context: object) => {
  return { test: 'toto', data: event['data'] };
}
```
- play those requests in Altair:
mutation UpsertFunction($file: Upload!) {
  upsertFunction(name: "toto", file: $file)
}

mutation ExecFunction {
  executeFunction(name:"toto", payload: {data: "titi"})
}
- it will run the local driver, add those env variable to test with
lambda driver
```
CUSTOM_CODE_ENGINE_DRIVER_TYPE=lambda
LAMBDA_REGION=eu-west-2
LAMBDA_ROLE=<ASK_ME>
```

packages/twenty-website/src/content/developers/self-hosting/self-hosting-var.mdx

@@ -147,6 +147,16 @@ yarn command:prod cron:calendar:calendar-event-list-fetch
     ['STORAGE_LOCAL_PATH', '.local-storage', 'data path (local storage)'],
     ]}></ArticleTable>
 
+### Custom Code Execution
+
+<ArticleTable options={[
+  ['SERVERLESS_TYPE', 'local', "Serverless driver type: 'local' or 'lambda'"],
+  ['SERVERLESS_LAMBDA_REGION', '', 'Lambda Region'],
+  ['SERVERLESS_LAMBDA_ROLE', '', 'Lambda Role'],
+  ['SERVERLESS_LAMBDA_ACCESS_KEY_ID', '', 'Optional depending on the authentication method'],
+  ['SERVERLESS_LAMBDA_SECRET_ACCESS_KEY', '', 'Optional depending on the authentication method'],
+]}></ArticleTable>
+
 ### Message Queue
 
 <ArticleTable options={[