Allow upload ssl certificates for a specifc zone

### The required feature described as a wish

As a User/Admin/Operator I would like to ,upload custom SSL for specific zone

Currently the certificate applies to all the zones once uploaded

The API also doesn't have the zone id parameter

https://cloudstack.apache.org/api/apidocs-4.21/apis/uploadCustomCertificate.html

There is a pr which moves the console proxy configuration from global level to zone level

https://github.com/apache/cloudstack/pull/11415

It would be beneficial for the operator to have certificates at zone level

首先閱讀 uploadCustomCertificate API 文件和相關的 PR #11415，該 PR 將 console proxy 設定從全域層級移至 zone 層級。追蹤目前憑證上傳與 zone 設定之間的連結方式。當操作員可以為一個 zone 上傳自訂憑證，而不變更其他 zone 的憑證，且 API 中表示了 zone ID 時，即表示完成。

由索引模型根據 Issue 內容生成。