JSON Serialization Issue with Binary Data in ClickHouse Metadata

We happened to use JSON serialization for some metadata, which was a mistake, because JSON does not support binary data inside string literals, including zero bytes. SQL queries can contain binary data and invalid UTF-8, so we have to support this in our metadata files as well. At the same time, ClickHouse's JSONEachRow and similar formats work around that by deviating from the JSON standard in favor of a perfect roundtrip for the binary data. See the motivation here: https://github.com/ClickHouse/ClickHouse/pull/73668#issuecomment-2560501790. The solution is to make Poco::JSON library consistent with the JSON format serialization in ClickHouse. This closes #73668. #75963 (Alexey Milovidov).