[Task] Some of the sample guidance conforms to business usage

### Pre-check

- [X] I am sure that all the content I provide is in English.

### Search before asking

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

### Apache Dubbo Component

Java Samples (apache/dubbo-samples)

### Descriptions

1. EmbeddedZookeeper: Change to a regular zookeeper download, install startup commands
2. Change samples to normal applications instead of directly loading XML within the Main function.

### Related issues

https://github.com/apache/dubbo/discussions/13847

### Are you willing to submit a pull request to fix on your own?

- [ ] Yes I am willing to submit a pull request on my own!

### Code of Conduct

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