[core] Introduce Flink 'CreateGlobalIndexProcedure'

[JingsongLi]

Purpose

This Pull Request implements a BTree Global Index Builder for Flink in Apache Paimon, introducing the CreateGlobalIndexProcedure functionality.

Key Features

• Global Index Creation: Enables users to create global BTree indexes on Paimon tables using Flink
• BTree Index Support: Implements BTree-based indexing structure for efficient data lookup
• Flink Integration: Integrates the global index creation process with Flink's data processing pipeline
• Procedure API: Provides a SQL procedure interface (sys.create_global_index) for creating indexes

Tests

The PR includes integration tests (BTreeGlobalIndexITCase).

API and Format

Documentation

[steFaiz]

Thanks for this PR!