Describe
str_to_map(text[, pairDelim[, keyValueDelim]]) is not supported in Auron’s native execution path, so queries using it fall back instead of being executed natively.

Describe the solution you'd like
Add native support for Spark str_to_map(...) through the extension-function path.

The implementation should keep Spark semantics aligned:

• split text into key/value pairs using delimiters
• use default delimiters , for pairDelim and : for keyValueDelim
• treat both pairDelim and keyValueDelim as regular expressions
• preserve Spark-compatible parsing and null behavior
• add regression tests to verify semantic consistency with Spark