Update TranslateService.php

[itashia]

refactor(TranslateService): enhance readability, flexibility & error handling

• Renamed variables to more descriptive names (e.g., translate_from ➝ sourceLanguage)
• Added caching mechanism for repeated translations
• Introduced dry-run mode to allow testing without saving
• Added option to disable parameter preservation
• Improved error messages for better debugging
• Added strict type hints for better static analysis
• Split large methods into smaller single-responsibility methods
• Validated source and target languages for correctness

Thank you so much for your thoughtful feedback and contributions — you've made this service cleaner, smarter, and easier to maintain. 🙏