[AINode] Update AINodeClient for DataNode to borrow

[Alchuang22-dev]

Description

This PR refactors the AINode client infrastructure to support direct communication between DataNode and AINode, removing the dependency on ConfigNode for AI-related operations such as model loading and inference. Should be reviewed by @CRZbulabula

Contents

AINodeClient

• Added a new executeRemoteCallWithRetry() method for automatic retry and reconnection on Thrift transport failures, following the same design pattern as ConfigNodeClient.

• Updated the loadModel(TLoadModelReq req) API to use this retry wrapper for improved resilience.

• Simplified connection lifecycle management (init(), close()) to ensure stable client reuse via AINodeClientManager.

ClusterConfigTaskExecutor

• Replaced indirect ConfigNode RPCs with direct calls to AINodeClientManager.borrowClient(TEndPoint) for model operations (currently loadModel as an example).

• Ensured the DataNode→AINode invocation flow mirrors the ConfigNode client style while maintaining compatibility with existing client pooling.

• Updated Thrift imports to use org.apache.iotdb.ainode.rpc.thrift.* instead of org.apache.iotdb.confignode.rpc.thrift.*.

AINodeClientManager

• No functional changes; reused existing pool management for TEndPoint-based clients to keep consistency with ConfigNodeClientManager.

Impact

DataNode can now directly send AI-related requests (e.g., model load/unload, inference) to AINode without routing through ConfigNode.

Next Steps

Extend the same direct invocation pattern (AINodeClientManager.borrowClient()) to other AI APIs:
unloadModel, showModel, showLoadedModel, showAIDevices, createTraining, and getModelInfo.

---

This PR has:

• been self-reviewed.
  • concurrent read
  • concurrent write
  • concurrent read and write
• added documentation for new or modified features or behaviors.
• added Javadocs for most classes and all non-trivial methods.
• added or updated version, license, or notice information
• added comments explaining the "why" and the intent of the code wherever would not be obvious
  for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold
  for code coverage.
• added integration tests.
• been tested in a test IoTDB cluster.

---

Key changed/added classes (or packages if there are too many classes) in this PR

As former.

[CRZbulabula]

PTAL.

[CRZbulabula]

PTAL.

[CRZbulabula]

PTAL.

[CRZbulabula]

PTAL.

[CRZbulabula]

PTAL.

[RkGrit]

LGTM~

[CRZbulabula]

LGTM!!!