Support dictionary table function for RegExpTreeDictionary

Why it matters

This feature enables users to query RegExpTreeDictionary dictionaries directly using the dictionary table function, simplifying data access and integration by allowing dictionary data to be used as a table within SQL queries.

How to use it

Use the dictionary table function specifying a RegExpTreeDictionary dictionary name to query it like a regular table, for example:
sql<br>SELECT * FROM dictionary('your_regexp_tree_dictionary_name')<br>