[ISSUE-148] Support drop_table and list_offsets methods in python bin…

[fresh-borzoni]

Adds two missing admin operations to achieve feature parity with C++ bindings:

1. Admin.drop_table(table_path, ignore_if_not_exists=False)
   - Drop a table from the cluster
   - Optional flag to ignore if table doesn't exist

2. Admin.list_offsets(table_path, bucket_ids, offset_type, timestamp=None)
   - List offsets for specified buckets
   - offset_type: 0=Earliest, 1=Latest, 2=Timestamp
   - Returns dict[int, int] mapping bucket_id to offset

Implementation follows existing patterns from create_table() and matches
C++ bindings logic. Both core APIs already existed in admin.rs.

Closes #148

[Copilot]

Pull request overview

This PR adds two administrative operations to the Python bindings to achieve feature parity with C++ bindings: drop_table() for deleting tables and list_offsets() for querying bucket offsets. Both methods follow existing async patterns and leverage core APIs that already exist in the Rust codebase.

Changes:

• Added Admin.drop_table() method with optional ignore_if_not_exists parameter
• Added Admin.list_offsets() method supporting earliest, latest, and timestamp-based offset queries
• Introduced OffsetType class with string constants for type-safe offset type specification
• Updated example.py to demonstrate both new features

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
bindings/python/src/lib.rs	Adds OffsetType class definition with string constants and registers it in the Python module
bindings/python/src/admin.rs	Implements drop_table() and list_offsets() admin methods with validation and error handling
bindings/python/example/example.py	Demonstrates usage of new methods with both string literals and OffsetType constants

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[fresh-borzoni]

resolved conflict

[fresh-borzoni]

@luoyuxia PTAL 🙏