Add a middle layer of agents to enhance standalone IoTDB with full-fledged scalable distributed system properties

**Is your feature request related to a problem? Please describe.**

This is an enhancement feature that shall extend standalone IoTDB with scalability.
The goal of this feature is to **add a middle layer of agents to enhance standalone IoTDB with full-fledged scalable distributed system properties. **

**Describe the solution you'd like**

Would like to add a middle of stateless agents that can orchestrate a set of standalone IoTDB instances to form a full-fledged scalable distributed system.

Each of such stateless agents should at least function like [IKR](https://github.com/thulab/iotdb-kairosdb), except for 1) not supporting JSON interface at the moment; 2) support the native IoTDB session interfaces; 3) support data partitioning and sharding for the initial implementation.

**Describe alternatives you've considered**

Believe no alternatives should exist.

**Additional context**

IginX is a possible name for the agent.

まず、スタンドアロン IoTDB のアーキテクチャとリンクされている IKR プロジェクトを確認し、提案されているエージェント層を理解します。次に、スタンドアロンインスタンス間で native IoTDB session interfaces、データパーティショニング、シャーディングをどのように機能させる必要があるかを検討します。完了条件は、これらの初期機能を備えたステートレスエージェントの合意済み設計と実装です。

索引モデルが issue の本文から書いたものです。