Client expiration handling issue: 401 Unauthorized errors wrapped as 500 Internal Server Error

### Expected Behaviour
According to the documentation, the `refreshClient` function should be called when the ACC session expires due to token expiration. This allows the client to refresh the token and retry the failed SOAP call.

### Actual Behaviour
When the token expires, the refresh callback never called, and the sdk returns a 500 Internal Server Error with the following error message:
```yml
CampaignException {
name: 'CampaignException',
message: "500 - Error SOAP-ENV:Client calling method 'xtk:persist#GetEntityIfMoreRecent': SOP-330007 Error while reading parameters of method 'GetEntityIfMoreRecent' of service 'xtk:persist'. XSV-350114 Unknown error during '/ims/profile/v1' IMS call, HTTP response code is 401",
statusCode: 500,
// ... (rest of the error object)
}
```
The error message indicates that the underlying issue is a 401 Unauthorized error, but it's being wrapped as a 500 Internal Server Error. As a result, the SDK's condition `ex.statusCode == 401` is not met, and the `refreshClient` function is never called.

```js
// Call session expiration callback in case of 401
if (ex.statusCode == 401 && that._refreshClient && soapCall.retry) {
return this._retrySoapCall(soapCall);
} else
return Promise.reject(ex);
```

### Reproduce Scenario (including but not limited to)

#### Steps to Reproduce
1. Initialize the SDK with a `refreshClient` function, similar to the following:

```js
const connectionParameters = sdk.ConnectionParameters.ofImsBearerToken(
"https://myInstance.campaign.adobe.com",
"ims_bearer_token",
{
timeout: 10000,
refreshClient: async (client) => {
// Token refresh logic here
return client;
}
}
);
```
2. Perform a SOAP call that requires an active token.
3. Wait 24hrs for the token to expire. (or you can sipmly try with invalid one, to see if the refresh callback will be called once)
4. Observe the 500 Internal Server Error with the error message indicating a 401 Unauthorized error.

#### Platform and Version
- NestJS
- @adobe/acc-js-sdk: "^1.1.47",

Start at the SOAP-call error handling shown around the refreshClient condition and _retrySoapCall, then trace how the underlying 401 response becomes CampaignException.statusCode 500. Reproduce with an expired or invalid token and verify that refreshClient is invoked and the failed SOAP call is retried.

Written by the indexing model from the issue text.