fix: support quoted select aliases

[shurarama]

Summary

• Normalize quoted SELECT aliases by removing CQL double quotes before storing response metadata.
• Emit non-bare or reserved aliases as Bigtable SQL backtick identifiers so valid Cassandra aliases like AS "TableBindName" and AS "select" prepare successfully.
• Add regression coverage for quoted column, aggregate, WRITETIME, GROUP BY, and ORDER BY aliases.

Test plan

• go test ./translators/select_translator -run TestTranslator_TranslateSelectQuerytoBigtable -count=1
• go test ./parser ./translators/...
• Verified the new alias tests fail on the pre-fix code in a clean temporary worktree.

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[gemini-code-assist]

Code Review

This pull request introduces support for quoted aliases in the CQL-to-Bigtable SQL translation layer, ensuring that aliases in SELECT, GROUP BY, and ORDER BY clauses are correctly formatted with backticks when necessary. Feedback indicates that the alias formatting logic needs to escape backslashes in addition to backticks to prevent syntax errors in GoogleSQL. Additionally, the check for bare identifiers should be updated to use Bigtable SQL reserved keywords rather than CQL keywords to ensure full compatibility with the target environment.