feat: add v5.8.0 package updates

[onesignal-deploy]

Release v5.8.0

🚀 Features

• feat: [SDK-4438] add typed error-messages accessor to ApiException
• feat: [SDK-4440] generate typed error-code catalog module per SDK
• feat: [SDK-4441] add idempotency-key retry helper for create-notification
• feat: [SDK-4441] expose createNotificationWithRetry as a client method
• feat: [SDK-4441] clamp retry helper backoff base to [1s, 60s]
• feat: [SDK-4776] expose time_offset pagination on get_notifications
• feat: [SDK-4781] add message-sent/not-sent narrowing helpers
• feat: [SDK-4781] refine narrowing-helper doc nudge and PHP null-safety

🐛 Bug Fixes

• fix: [SDK-4438] narrow TS errorMessages title type and keep empty strings
• fix: [SDK-4440] reclassify OVER_SUBSCRIBER_LIMIT as a template entry
• fix: [SDK-4438] surface object-shaped errors in error-messages accessors
• fix: [SDK-4440] trim OneSignalErrors catalog to a verified minimal set
• fix: [SDK-4776] append time_offset after kind in get_notifications

📚 Docs

• docs: demonstrate polymorphic response handling for POST /notifications
• docs: fix polymorphic createNotification example correctness across SDKs
• docs: add common-patterns preamble to each SDK's DefaultApi.md
• docs: revise common-patterns preamble per-language and drop jargon
• docs: revise preamble wording per PR #392 review feedback
• docs: correct preamble auth claim + Go error-handling pointer prose
• docs: tighten preamble error-handling section (Go nil-check + 4th envelope shape)
• docs: [SDK-4441] add createNotificationWithRetry example to DefaultApi docs
• docs: [SDK-4440] fix OneSignalErrors usage example for the 200-status sentinel
• docs: clarify errorMessages excludes structured meta; show how to read it
• docs: demonstrate reading 409 conflict meta in CreateUser example
• docs: [SDK-4440] cross-link OneSignalErrors catalog from DefaultApi.md error handling

---

Generated from OneSignal/api-client-libraries@80e7333...2907ac8.

[onesignal-deploy]

Superseded by v5.8.0 release.