UI : Show the Backup repository as column in Backup offerings view

### The required feature described as a wish

Currently, if there are multiple back up repository in Cloudstack

Its difficult to identify the backup offerings associated with the backup repository from the UI.

Expected behaviour

It would be great if the backup column is added to the backup offerings view

also the backup repoistory is mentioned as External id (uuid) it would be great if the backup reposistory name is mentioned

https://cloudstack.apache.org/api/apidocs-4.22/apis/listBackupRepositories.html
https://cloudstack.apache.org/api/apidocs-4.22/apis/listBackupOfferings.html

先查看 issue 中链接的 listBackupRepositories 和 listBackupOfferings API 文档，然后定位 Backup Offerings 视图，并确定其当前的仓库标识符是如何填充的。对于与多个仓库关联的 offerings，如果该视图显示包含仓库名称的备份仓库列，而不只是其外部 ID，则视为完成。

由索引模型根据 Issue 内容生成。