Support input data for reading from the URL table engine #45994
Description
Allow to POST data to the HTTP server from a subquery and receive the result.
Similarly to the Executable table engine, see https://presentations.clickhouse.com/meetup56/new_features/index.html#9
It can be used for data transformations.
Also, remote *CGI scripts can represent serverless functions.
Additional context
Support for user-defined functions with the URL engine is also tempting.