Add APIError class with HTTP error parsing

[parthban-db]

🥞 Stacked PR

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• stack/port-api-error [Files changed]
  • stack/update-agent-metadata-3 [Files changed]
    • stack/api-execute-retrier [Files changed]
      • stack/update-agent-metadata-4 [Files changed]

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What changes are proposed in this pull request?

Add the core APIError class and fromHttpError factory function, ported from the Go SDK's apierr/apierr.go. This is the main error type that will be returned by all Databricks API calls.

• APIError — a transport-agnostic error class extending Error with code, message, details, and HTTP metadata (status code, headers, body).
• fromHttpError(statusCode, header, body) — parses HTTP error responses into APIError, handling standard, legacy (API 1.2), and SCIM error formats. Returns undefined for 2xx status codes.
• toCode(httpCode) — maps HTTP status codes to canonical Code values (e.g. 404 → NOT_FOUND, 429 → RESOURCE_EXHAUSTED).
• Uses a Zod schema for lenient JSON body parsing, supporting error_code as string or integer, multiple message fields (message, error, detail, scimType), and structured error details.

How is this tested?

Unit tests.