Option to Disable Auto-Escaping During Parsing

Summary: Many users of PapaParse may encounter CSV files that contain pre-escaped characters. In the current implementation, PapaParse automatically adds escaping to these characters, which results in double-escaped characters in the output. This behavior can be problematic for CSVs that are expected to contain escape characters as part of the data.

Issue: When parsing a CSV with pre-escaped quotes (either with a backslash or double quotes), PapaParse's parser automatically escapes these characters, leading to an unexpected doubling of escape characters in the output.

For example, an input CSV line like: "Test \"Test string\" Test","Definitely \"real\" cash" gets parsed to: ["Test \\\"Test string\\\" Test", "Definitely \\\"real\\\" cash"] instead of the expected: ["Test \"Test string\" Test", "Definitely \"real\" cash"]

Similarly, a value enclosed in triple quotes to signify an internal quote like: """Test \"Test string\" Test""" results in: ["\"Test \\\"Test string\\\" Test\""] which should ideally remain: ["""Test \"Test string\" Test"""]

Feature Request: It would be beneficial to have an option to disable auto-escaping entirely when parsing CSV files. This would allow users to work with CSV data that already includes the necessary escaping and expects it to be preserved as-is.