Added output_format_json_escape_forward_slashes Option

Why it matters

This feature allows users to configure whether forward slashes are escaped or not in JSON output, helping to improve compatibility and readability of JSON produced by ClickHouse, especially when consumed by different clients or systems that may treat escaped slashes differently.

How to use it

To enable or disable escaping of forward slashes in JSON output, set the output_format_json_escape_forward_slashes setting to 1 (to escape) or 0 (to not escape). This can be done in the query settings or the server configuration.