fix(sagemaker): Fix race-condition with multiple remote spaces trying to reconnect

[aws-asolidu]

Problem

• When reconnecting to multiple SageMaker Spaces (either via deeplink or from within the VS Code extension), a race condition occurs when writing to shared temporary files. This can cause the local SageMaker server to crash due to concurrent access.
• Need clearer error messaging when reconnection to a deeplinked space is attempted without an active Studio login.

Solution

• For connections initiated from the VS Code extension, we generate unique temporary files to read the response json.
• For deeplink-based reconnections, we introduce a queue to process session requests sequentially.
• Add remote_access_token_refresh flag to the refresh URL to enable the Studio server to return more specific error messages.

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• Treat all work as PUBLIC. Private feature/x branches will not be squash-merged at release time.
• Your code changes must meet the guidelines in CONTRIBUTING.md.
• License: I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

• This pull request implements a feat or fix, so it must include a changelog entry (unless the fix is for an unreleased feature). Review the changelog guidelines.
  • Note: beta or "experiment" features that have active users should announce fixes in the changelog.
  • If this is not a feature or fix, use an appropriate type from the title guidelines. For example, telemetry-only changes should use the telemetry type.

[NewtonDer]

Need to generate a changelog entry with npm run newChange -w packages/toolkit

[leigaol]

processWriteQueue().catch this catch cannot catch anything because inside processWriteQueue it does not throw.

[aws-asolidu]

Thanks, I’ll remove this. Since processWriteQueue uses a try/finally block there's nothing to catch, and writeOperation already handles errors and calls reject.