Remove deprecated Compiler.compile wrapper

[nthbotast]

Summary

Implements #7 by removing the deprecated Compiler.compile() wrapper in data_diff/databases/base.py.

What changed

• Removed deprecated method:
  • Compiler.compile(self, elem, params=None)
• Updated test callers to use the canonical path directly:
  • compiler.dialect.compile(compiler, expr)

This removes deprecated API surface and keeps callsites explicit.

Notes

I also updated the affected tests (tests/test_query.py, tests/test_sql.py) to reflect the new usage.

[dtsong]

Thanks for the contribution! However, this work was already completed in PR #17 (commit f070d2b), which removed the deprecated Compiler.compile() wrapper and updated all test callsites.

Since master already reflects these changes, I'm going to close this one out. If you're interested in contributing, we have several open issues that could use help — feel free to take a look!