Refactor error message formatting in BadJpqlGrammarErrorListener

[jbh010204]

This pull request refactors the error message formatting logic in BadJpqlGrammarErrorListener to improve readability, maintainability, and robustness. The main changes involve switching from string concatenation to using a StringBuilder, introducing a helper method for line extraction, and refining how error messages are constructed for different types of exceptions.

Error message formatting improvements:

• Refactored the formatMessage method to use a StringBuilder instead of string concatenation, making the code more efficient and easier to read.
• Improved handling of error messages for NoViableAltException by extracting the relevant line from the query and inserting a marker at the offending character position, using the new getLineAt helper method.
• Added the private static getLineAt method to safely retrieve the appropriate line from the query string, handling edge cases where the line number may be out of bounds.
• Enhanced error message construction for InputMismatchException by clarifying the expected tokens in the output.

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[mp911de]

to improve readability, maintainability

The new variant is less readable and it doesn't fix any problem therefore we want to keep the code as-is.