[Feat][Connector-v2][Iceberg]support filter conditions in iceberg source

[litiliu]

Purpose of this pull request

close #9081

Does this PR introduce any user-facing change?

Updated Doc

How was this patch tested?

Unit test and E2E case added

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
• Update the release-note.

[Copilot]

Pull Request Overview

This pull request enhances the Iceberg connector by adding support for filtering data using SQL-like WHERE clauses. Key changes include new tests for SQL-to-Iceberg expression conversion, updates to the expression converter to handle various SQL expressions, and documentation updates for the new "where_clause" option.

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

File	Description
connector-iceberg/src/test/java/org/apache/seatunnel/connectors/seatunnel/iceberg/config/SQLToIcebergExprConverterTest.java	Added comprehensive tests covering various SQL expressions.
connector-iceberg/src/main/java/org/apache/seatunnel/connectors/seatunnel/iceberg/config/SQLToIcebergExprConverter.java	Implements the conversion from SQL to Iceberg expressions with potential issue in NullValue handling.
connector-iceberg/src/main/java/org/apache/seatunnel/connectors/seatunnel/iceberg/config/IcebergSourceOptions.java	Introduces the new "where_clause" option.
docs/en/connector-v2/source/Iceberg.md	Updates documentation to include the new filtering option.

Files not reviewed (1)

• seatunnel-connectors-v2/connector-iceberg/pom.xml: Language not supported

[hailin0]

Please add a testcase