Refactor C# client documentation

[bernardlim]

Summary

This PR improves the ClickHouse C# Driver documentation by fixing errors, adding missing information, and updating outdated examples.

Key Changes:

• Updated namespace references from ClickHouse.Client.ADO to ClickHouse.Driver.ADO throughout examples
• Enhanced "Supported Data Types" section with complete .NET type mappings (e.g., Int8 → sbyte, UInt64 → ulong)
• Added missing data types: Decimal128, Map(K, V) → Dictionary<K, V>
• Reorganized numeric types into clearer subcategories (Signed Integers, Unsigned Integers, Floating Point, Decimal)
• Migrated additional examples and best practices from old wiki documentation
• Improved code example formatting for consistency

Checklist

• Updated documentation content only (no URL changes required)
• Fixed namespace inconsistencies (ClickHouse.Client → ClickHouse.Driver)
• Added missing data type mappings for developer reference
• Verified all code examples compile with current ClickHouse.Driver package
• Maintained existing anchor IDs to preserve external links

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