[Enhancement] Add a load balance strategy: source ip hash

### Search before asking

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

### Enhancement Request

Add a load balance strategy: source ip hash. Make the request from the same machine always arrive at the same server.

### Describe the solution you'd like

Add a new LoadBalanceSelector for implementing source ip hash algorithm.
Add unit test for new LoadBalanceSelector.

### Are you willing to submit PR?

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

Search the project for existing LoadBalanceSelector implementations and their unit tests, then read how the selector receives request source information. Add coverage for the new source-IP hash selector, with tests showing that requests from the same source are consistently routed to the same server.

Written by the indexing model from the issue text.