extend new tracing instrumentation for the SDK

[lucix-aws]

Tracks and extends changes in https://github.com/aws/smithy-go/pull/534

Tracing component of #1744

• wraps the retry loop in a span (an outer one for retry loop, and then span per-attempt)
• adds the following span attributes
  • operation.attempt - the number of the current attempt, starting at 1
  • aws.request_id - aws request ID (set per attempt)
  • aws.extended_request_id - additional request ID returned from some services (i.e. just s3 right now)
  • net.peer.name - the host:port combination that the HTTP client DialContext()ed
  • net.peer.host - IP address returned from the inner dial
  • net.peer.port - port returned from the inner dial
  • net.peer.addr - raw ip:port combination that the dial returned, if it couldn't be parsed into host/port separately for some reason

[lucix-aws]

~~taking a look at test failures~~

[EDIT] fixed, I think