[Improve] ElasticSearch service address configuration supports the following two formats

[zhangshenghang]

Purpose of this pull request

ElasticSearch service address configuration supports the following two formats:

1. Single node mode: a single string, such as "127.0.0.1:9200"
2. Cluster mode: JSON array string, such as ["127.0.0.1:9200", "127.0.0.2:9200"]

Check list

• Code changed are covered with tests, or it does not need tests for reason:
• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs

[Hisoka-X]

I’m not sure if this special handling is necessary, because there are still a lot of array parameters, do we have to adapt to all of them?

[zhangshenghang]

I’m not sure if this special handling is necessary, because there are still a lot of array parameters, do we have to adapt to all of them?

@Hisoka-X I think this modification will make it very convenient for users to use.