[FEATURE] Make external KV store as an option to store session and operation handles

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

### Search before asking

- [X] I have searched in the [issues](https://github.com/apache/incubator-kyuubi/issues?q=is%3Aissue) and found no similar issues.

### Describe the feature

Currently, we use in-memory maps to store session and operation handles, is it possible to store them via leveldb, zookeeper, redis? Then we can make kyuubi server free to rebooting as the actual executions are on the engine side

### Motivation

make kyuubi server stateless

### Describe the solution

_No response_

### Additional context

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

The issue names no files, tests, or entry points; start by locating the in-memory session and operation-handle maps. Define how an external store such as Redis would be selected and how handles survive a Kyuubi server restart, then verify that the server can reboot while executions continue on the engine side.

Written by the indexing model from the issue text.