[Feature][QDP] Introduce object store registry for remote URL providers

[400Ping]

Goal

Refactor remote URL provider selection to a registry-based pattern so new providers can be added with minimal core changes.

Scope

• Introduce a provider registry abstraction in qdp-core remote I/O path.
• Register current providers (s3, gs) via provider factories.
• Replace direct scheme match logic with registry lookup.
• Keep current behavior unchanged:
  • supported schemes remain s3://, gs://
  • query/fragment remains unsupported
  • temp-file download flow remains unchanged
• Add/adjust tests for:
  • known scheme resolution
  • unknown scheme rejection
  • provider registration behavior