Add Zenoh subscription plugin with topic-to-label mapping and schema attachments #2

Problem
Users need Zenoh support in reduct-bridge. A user should be able to describe Zenoh topic subscriptions in TOML, map values from Zenoh messages to ReductStore labels before sending, and store message schemas as entry attachments.

Proposed solution
Implement Zenoh support as a plugin-based integration.

• Add ReductStore connection parameters in plugin configuration.
• Add Zenoh connection configuration where each connection defines:
  • target bucket name
  • subscribed topics list with wildcard support
  • label mappings from message fields to ReductStore labels, for example zenoh/topic.x -> "topic_x".
• Publish raw Zenoh messages to ReductStore (no conversion to MCAP or rosbag formats).
• Store message schemas as ReductStore entry attachments.

Scope / constraints (v1)

• In scope: plugin architecture, TOML config, wildcard topic subscription, label mapping, raw message forwarding, schema attachments.
• Out of scope: custom message handling workflows, MCAP conversion, rosbag conversion.