CDF-26312: Client: allow customizing sttp client by wrapping too (better retries)

[dmivankov]

Currently Client accepts base client and wraps it with tracing&auth
headers. So to add retries the flow was making base sttp client retrying.
This may run into issue of expiring auth header, auth provider would've
refreshed it if it was called, but all retrying happens below it.

Now adding optional parameter to customize sttp client by wrapping,
intent is for calller to add retries by wrapping making each try request
auth again and have a chance to refresh it if it expires soon

CDF-26312

[gemini-code-assist]

Code Review

This pull request introduces a wrapSttpBackend parameter to RequestSession to allow for more flexible customization of the sttp client, particularly for implementing retry logic that re-authenticates on each attempt. While the change in RequestSession is correct, the new functionality is not exposed to the client's users because GenericClient has not been updated to accept and pass this new parameter. This is a critical issue that prevents the feature from being used.

[gemini-code-assist]

The addition of wrapSttpBackend to RequestSession is a good approach to allow for more flexible client customization. However, this new functionality is not currently exposed to the end-user.

The GenericClient is responsible for creating the RequestSession, but it has not been updated to accept or pass along the wrapSttpBackend function. As a result, the RequestSession will always be created with the default identity wrapper, and the new feature will be unusable.

To complete this feature, you'll need to thread the wrapSttpBackend parameter through GenericClient's constructors and factory methods, and use it when instantiating RequestSession.