feat(table): add delete files metadata table

[fallintoplace]

Summary

Adds the live delete_files metadata table to Table.Inspect.

• Supports equality-delete, position-delete, and deletion-vector file metadata.
• Reuses the content-file schema, metrics, partition values, bounds, and v3 fields from feat(table): add data files metadata table #1698.
• Keeps delete-file metadata separate from delete-file record reading.

Tests

• go test ./table
• Covers the shared content-file schema and decimal partition values.

Scope

This is metadata inspection only. Delete application and delete-file record reading are unchanged.

Related

Builds on #1698.