Consider to replace libevent with libuv

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/kvrocks/issues) and found no similar issues.

### Motivation

The development of libevent seems tardy and no new release since 2020 (5 years ago).

We should consider to replace it via other event libraries like libuv: https://github.com/libuv/libuv, which is used by nodejs, rust, julia and more.

Another good choice is boost::asio but it involves massive changes to existing kvrocks codebase.

### Solution

_No response_

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

The issue does not identify files, tests, or an entry point. Start by locating the existing libevent integration and mapping the event-loop interfaces it exposes; compare libuv and boost::asio against those uses. Done means the selected replacement works across the existing event-driven paths with appropriate tests and no libevent dependency.

Written by the indexing model from the issue text.