[ENG-337] improve secret imports CRUD resource

[Pierre-Green]

Feature Description

Currently, the POST, PUT, and DELETE endpoints for secret imports respond with a success message (HTTP CODE 200). The proposed enhancement involves having these endpoints return an object containing the secretImport field, similar to the behavior of the GET endpoint.

Why would it be useful?

Aligning the response format of these endpoints with other CRUD resources, such as secrets, which return objects instead of plain messages, would provide consistency. Additionally, this change is essential for implementing a comprehensive terraform resource for secret-imports.

Additional context

I've initiated a draft PR in the terraform provider repository to facilitate the management of secret imports, which can be found here: Terraform Provider Infisical PR #26.

_{From SyncLinear.com | ENG-337}

[akhilmhdh]

Closing as stale and fixed with new backend