Added dictionary table function resembling Dictionary engine

Why it matters

This feature enables querying dictionaries via a table function, allowing more flexible and convenient usage of dictionaries within SQL queries. It solves the limitation of only accessing dictionaries through engine tables, enhancing composability and usability.

How to use it

Use the dictionary table function in your queries to access a dictionary by its name, for example:

SELECT * FROM dictionary('dictionary_name')

Replace dictionary_name with the actual dictionary identifier defined in your ClickHouse configuration.