[FEATURE REQ] Support renaming named values

[kwin]

Please describe the feature.

If a named value with the same displayName but a different name does already exist in APIM while publishing the following error is emitted

##[error]System.Net.Http.HttpRequestException: HTTP request to URI https://management.azure.com/subscriptions/***/resourceGroups/***/providers/Microsoft.ApiManagement/service/***/namedValues/MyNamedValue?api-version=2023-09-01-preview&asyncId=69c299e5f0b6541b0829f74c&asyncCode=201 failed with status code 400. Content is '{"error":{"code":"ValidationError","message":"One or more fields contain incorrect values:","details":[{"code":"ValidationError","target":"name","message":"Property with the same name already exist."}]}}'.

Currently this requires manual deletion of the existing named value before publishing succeeds. Would be nice to automatically such cases within the publisher client.

[github-actions]

  Thank you for opening this issue! Please be patient while we will look into it and get back to you as this is an open source project. In the meantime make sure you take a look at the [closed issues](https://github.com/Azure/apiops/issues?q=is%3Aissue+is%3Aclosed) in case your question has already been answered. Don't forget to provide any additional information if needed (e.g. scrubbed logs, detailed feature requests,etc.).
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