Flink: Implement Flink InputFormat and integrate it to FlinkCatalog

[JingsongLi]

The final user case can be:

-- In Flink SQL client

CREATE CATALOG iceberg WITH('type'='iceberg', 'catalog-type'='hadoop', 'warehouse'='file:/tmp/warehouse_path');
USE CATALOG iceberg;

-- Create a "default.my_table" Iceberg Hadoop table in "/tmp/warehouse_path".
-- CREATE TABLE my_table (a INT, b STRING, c STRING) PARTITIONED BY(c) WITH('type'='iceberg'); -- Not supported now.
-- INSERT INTO my_table VALUES (1, '1', '1'), (1, '2', '2'); -- Not supported now.

-- Support:
SELECT * FROM my_table; -- SELECT
SELECT a, c FROM my_table; -- projection push down
SELECT * FROM my_table WHERE c='2'; -- filter push down
SELECT * FROM my_table LIMIT 1; -- limit push down

The implementations can be:

• Implement FlinkInputFormat: implement SplitGenerator and RowDataReader.
• Integrate it to Catalog: Implement FlinkTableFactory and FlinkTableSource.

[github-actions]

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[github-actions]

This issue has been closed because it has not received any activity in the last 14 days since being marked as 'stale'