Add S3 custom 503 throttling detection

[RanVaknin]

Addresses #5414

S3's RestXML protocol sends the response's error information in the response body. Since S3 head* operations do not have a body, we need to infer what kind of exception it is from the error message. In case of throttling, S3 will send:

HTTP/1.1 503 Slow Down

We need to grab the status code (503) and status text ("Slow Down") and use those two to infer that the server throttled the request.

We already have an execution interceptor for S3 that extracts info from head operation responses. All this PR does is adds one more logic branch that handles extracting the error info from the slow down responses, and create the appropriate S3Exception that will get classified as ThrottlingException and will apply the appropriate retry mechanism

[joviegas]

In the Release notes can we add a line to say that earlier 503 S3 StatusMessage was Slow Down and not its SlowDown that way we communicate we are updating the status message of the S3 503 response status at client side.

[RanVaknin]

In the Release notes can we add a line to say that earlier 503 S3 StatusMessage was Slow Down and not its SlowDown that way we communicate we are updating the status message of the S3 503 response status at client side.

Status Message (returned in the response metadata) did not change, it's still Slow Down. The only thing that changed is the SDK's errorCode field (parsed from the response's xml body) went from null to SlowDown.

[sonarqubecloud]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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