[BUG] Workspace Publisher YAML File overload variables ignored

### Release version

v6.0.0.2-alpha.1.0.3

### Describe the bug

Hello team,

Can we get a sample publisher file for workspace configuration publishing?

I've been trying for the last couple of hours to overload namedValues or serviceUrls of the APIs inside the Workspaces, but to no success.

The regular sample YAML publisher file seems to not apply for Workspaces scenarios and the values inside of it are ignored by the publisher tool. What keys should we use within it to make the publisher tool aware of the values that need overloading?

Thank you!

### Expected behavior

YAML Publisher configuration values are not ignored on APIM and the destination APIM is updated with the correct values

### Actual behavior

The APIs and NamedValues get deployed in the Workspace with the values extracted from source APIM.

### Reproduction Steps

Using the Workspace supported ApiOps Toolkit extract a Workspace.

Try to overload the exported variables with the sample provided Publisher Configuration YAML

再現手順で説明されている Workspace の抽出とサンプルの Publisher Configuration YAML から始め、そのエクスポートされた変数を、宛先 APIM のデプロイ時に使用される値と比較します。必要な overload keys を特定し、ソース APIM の値ではなく namedValues と serviceUrls が適用されることを確認できれば完了です。

索引モデルが issue の本文から書いたものです。