Simplify TranslateOperator implementation across all drivers

[pseudomuto]

Replace switch statements with slice-based lookups for better maintainability and consistency. Adds supportedOperations slice to each driver following the same pattern as supportedFeatures.

[Copilot]

Pull Request Overview

This PR refactors the TranslateOperator method across PostgreSQL, MySQL, and ClickHouse drivers by replacing verbose switch statements with slice-based lookups. The change introduces a supportedOperations slice in each driver, following the same pattern as the existing supportedFeatures slice. Additionally, fixes an inconsistent variable naming issue in the ClickHouse driver (supportsFeatures → supportedFeatures).

• Introduces supportedOperations slice in each driver for cleaner operator validation
• Simplifies TranslateOperator logic using slices.Contains instead of switch cases
• Fixes variable naming inconsistency in ClickHouse driver

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
drivers/postgres/postgres.go	Adds supportedOperations slice and refactors TranslateOperator to use slice-based lookup
drivers/mysql/mysql.go	Adds supportedOperations slice, refactors TranslateOperator, and extracts ILIKE handling into separate condition
drivers/clickhouse/clickhouse.go	Adds supportedOperations slice, refactors TranslateOperator, and fixes supportsFeatures typo to supportedFeatures

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