[Feature][API] Support hocon style declare row type in generic type

[CheneyYin]

Purpose of this pull request

close:

• [Feature][API] Support hocon style declare row type in generic type #6124

This PR can keep backward compatibility. So, the following schema declaration is available.

schema {
  fields {
    # Hocon style declare row type in generic type
    map0 = "map<string, {c_int = int, c_string = string, c_row = {c_int = int}}>"
    # Json style declare row type in generic type
    map1 = "map<string, {\"c_int\":\"int\", \"c_string\":\"string\", \"c_row\":{\"c_int\":\"int\"}}>"
  }
}

Does this PR introduce any user-facing change?

Update schema-feature.md.

How was this patch tested?

Add new test cases.

Check list

• 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
• If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist
• Update the release-note.

[Hisoka-X]

Please add doc to schema-feature.md

[CheneyYin]

Please add doc to schema-feature.md

Done

[CheneyYin]

PTAL @Hisoka-X @hailin0

[Hisoka-X]

Thanks @CheneyYin !