chore(explain): improve the explain stmt

[ffengyu]

I hereby agree to the terms of the CLA available at: https://docs.databend.com/dev/policies/cla/

Summary

fixes: #17660

• Display type for expressions in explain stmt
• Format window function type field of Sort function in explain(logical) stmt

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[github-actions]

🤖 Smart Auto-retry Analysis (Retry 1)

Workflow: 16298285638

📊 Summary

• Total Jobs: 80
• Failed Jobs: 9
• Retryable: 0
• Code Issues: 9

❌ NO RETRY NEEDED

All failures appear to be code/test issues requiring manual fixes.

🔍 Job Details

• ❌ linux / test_stateless_standalone: Not retryable (Code/Test)
• ❌ linux / test_stateless_cluster: Not retryable (Code/Test)
• ❌ linux / sqllogic / standalone_no_table_meta_cache (no_table_meta_cache, http): Not retryable (Code/Test)
• ❌ linux / sqllogic / ee (parquet): Not retryable (Code/Test)
• ❌ linux / sqllogic / standalone_iceberg_tpch: Not retryable (Code/Test)
• ❌ linux / sqllogic / cluster (cluster, 2c8g, hybrid): Not retryable (Code/Test)
• ❌ linux / sqllogic / cluster (cluster, 2c8g, http): Not retryable (Code/Test)
• ❌ linux / sqllogic / standalone (standalone, 2c8g, http): Not retryable (Code/Test)
• ❌ linux / sqllogic / standalone (standalone, 2c8g, hybrid): Not retryable (Code/Test)

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🤖 About

Automated analysis using job annotations to distinguish infrastructure issues (auto-retried) from code/test issues (manual fixes needed).