Support querying system tables in paimon-cpp

According to the official Paimon docs, system tables are first-class query interfaces for table metadata, changelog analysis, and catalog-wide observability:
https://paimon.apache.org/docs/master/concepts/system-tables/

`paimon-cpp` currently lacks system table query support.
This request is to add system table query support in `paimon-cpp`, including:

- Data system tables (for example):
`snapshots`, `schemas`, `options`, `audit_log`, `binlog`, `ro`, `files`, `tags`, `branches`, `consumers`, `manifests`, `aggregation_fields`, `partitions`, `buckets`, `statistics`, `table_indexes`
- Global system tables under `sys` (for example):
`tables`, `partitions`, `all_table_options`, `catalog_options`

Expected outcome:
- Users can query system tables in C++ environments with behavior aligned to Paimon documentation.
- Core changelog observability use cases (including `audit_log` and `binlog`) are covered.
- Metadata and global catalog inspection via system tables are available in `paimon-cpp`.