【API】Support Deployment Approval Self-Approval Option in Public Rest API

概述 Summary

之前我们贡献的功能 Add approval settings "Prevent approval by MR merge triggerer" for Protect Environment | upstream Issue 在上游用户中反馈很好，并提出了 API 需求 https://gitlab.com/gitlab-org/gitlab/-/issues/381418#note_1254132068

Upstream 已创建对应 follow-up issue https://gitlab.com/gitlab-org/gitlab/-/issues/390756 ，由我们继续负责贡献