Support case-insensitive and dot-all matching in regexp_tree dictionaries

Why it matters

This feature enables more flexible and powerful pattern matching within regexp_tree dictionaries by allowing case-insensitive matches and dot-all mode, which considers newline characters in matches. It improves dictionary usability for diverse text processing scenarios where patterns should ignore case or include line breaks.

How to use it

Users can enable these modes by specifying the appropriate flags when creating or querying regexp_tree dictionaries. This typically involves setting pattern options to include case-insensitive and dot-all modifiers in the dictionary configuration or queries.