feat(deparser): add join fixtures for pretty printing tests

[pyramation]

feat(deparser): add join fixtures for pretty printing tests

Summary

Adds SQL fixtures for testing JOIN statement parsing and deparsing. These fixtures were extracted from snapshots in another repository and cleaned up (removed unnecessary quotes around column references like "t0.id" → t0.id).

The fixtures cover:

• Simple inner join
• Left outer join
• Multiple joins in a single query
• Joined tables with specific column selections
• Basic SELECT from a single table

Review & Testing Checklist for Human

• Verify the cleaned-up SQL is what was intended - the original snapshots had quoted column references like "t0.id" which I converted to proper t0.id syntax. If you wanted to test the quoted versions to investigate a potential parser bug, those should be added separately.
• Confirm the JOIN normalization in snapshots is expected (INNER JOIN → JOIN, LEFT OUTER JOIN → LEFT JOIN)
• Run npm test -- --testPathPatterns="joins-pretty" in packages/deparser to verify tests pass

Notes

• Link to Devin run: https://app.devin.ai/sessions/b476871fb6a44680af5e882a7f7b8853
• Requested by: Dan Lynch (@pyramation)

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