Add decodeURLFormComponent function to ClickHouse

Why it matters

This feature addresses the need for decoding URL form components which may encode spaces as plus signs (+), differing from typical URL encoding. It enables users to accurately decode query string parameters or form data where plus signs represent spaces, improving data extraction and processing reliability.

How to use it

Use the decodeURLFormComponent function in your queries to decode URL form-encoded strings. For example:

SELECT decodeURLFormComponent('param+with+spaces%21')

This will correctly decode plus signs as spaces and decode percent-encoded characters.