feat: support metadata tables

[xxchan]

In Iceberg Spark/Flink there are metadata tables that provide information around the table: https://iceberg.apache.org/docs/latest/spark-queries/#inspecting-tables

Supporting this in iceberg-rust allows other engines (like RisingWave) to support these "standard" metadata tables.

reference implementation:
- https://py.iceberg.apache.org/api/#inspecting-tables
- https://github.com/apache/iceberg-python/blob/main/pyiceberg/table/inspect.py#L58-L90

List of all metadata tables: https://github.com/apache/iceberg/blob/main/core/src/main/java/org/apache/iceberg/MetadataTableType.java#L23

• ENTRIES
• FILES
• DATA_FILES
• DELETE_FILES
• HISTORY
• METADATA_LOG_ENTRIES
• SNAPSHOTS feat: support metadata table "snapshots" #822
• REFS
• MANIFESTS
• PARTITIONS
• ALL_DATA_FILES
• ALL_DELETE_FILES
• ALL_FILES
• ALL_MANIFESTS
• ALL_ENTRIES
• POSITION_DELETES

[Fokko]

Thanks for working on this @xxchan. Metadata tables are very important when it comes to the metadata operations. For example, the snapshots table in #822 will make it easy to perform operations like expiring snapshots.