[Improve][Connector-V2] Add branch option for paimon sink

[xiaochen-zhou]

Purpose of this pull request

Add branch option for paimon sink

sink {
  Paimon {
    warehouse = "/tmp/seatunnel_mnt/paimon"
    database = "default"
    table = "st_test_p"
    branch = "test-branch"
  }
}

Does this PR introduce any user-facing change?

Yes

How was this patch tested?

Add new e2e tests: PaimonSinkBranchIT

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 plugin-mapping.properties and add new connector information in it
  2. Update the pom file of seatunnel-dist
  3. Add ci label in label-scope-conf
  4. Add e2e testcase in seatunnel-e2e
  5. Update connector plugin_config

[davidzollo]

Should PaimonSaveModeHandler also handle it?
Considering that schema_save_mode = "RECREATE_SCHEMA"

    Table paimonTable = ((PaimonCatalog) catalog).getPaimonTable(tablePath);