Add storage to otlp reciver

[MJarmo]

Add persistent storage support to OTLP receiver

Summary

Introduces persistent storage support for the OTLP receiver to persist incoming telemetry (logs/traces/metrics) before export.

Goal

Prevent losing logs on high load/temporary backend outages by persisting queued telemetry.

Key changes

• Add storage/persistence integration to the OTLP receiver (file-based storage extension wiring).
• Ensure queue/receiver flow writes to persistent storage when configured.
• Fixes and improvements:
  • Fixes losing logs during receiver shutdown or high load.
  • Fix context propagation/usage in receiver code paths.
  • Lint/test fixes and naming improvements.
  • Prevent unkeyed composite literal usages.
• Tests updated/fixed to reflect new storage behavior.

Motivation

• Improve durability for audit/logging use-cases where telemetry must not be lost.
• Allow the Collector to act as a reliable ingestion point by persisting incoming data when configured.

Behavioral notes

• Persistent storage is opt-in via receiver configuration (storage extension). Default behavior remains unchanged unless storage is enabled in config.
• When enabled, OTLP receiver persists incoming items to configured storage backend and reads them for export, reducing the risk of data loss on collector restart or exporter unavailability.

Testing performed

• Unit tests updated and fixed.
• New/updated tests to ensure persistence behavior and that logs are not lost.
• Lint and build checks applied.

How to validate

• Enable storage extension and configure OTLP receiver to use it.
• Simulate exporter downtime or restart the collector; verify persisted telemetry is replayed on recovery.
• Verify behavior without storage remains same as before (no persistence).

Compatibility / Migration

• Backwards compatible: if no storage is configured, receiver behaves as before.
• Configuration changes required only to opt-in to persistence.

Request for reviewers

• Verify correctness of storage wiring and lifecycle handling.
• Validate that no data duplication occurs during replay.
• Review error paths and shutdown behavior to ensure clean shutdown without data loss.

Related

• Addresses reliability requirements for audit logging and long-term retention scenarios.