Don't visit the AST for UDFs if none are registered

[Algunenano]

Changelog category (leave one):

• Performance Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

• Don't visit the AST for UDFs if none are registered

Information about CI checks: https://clickhouse.com/docs/en/development/continuous-integration/

More work to reduce query interpretation (#39996)

In this case perf is showing that ~1% of the query (in the query for #40065) is spent on the UserDefinedSQLFunctionMatcher visitor:

-    1.05%     0.23%           755  TCPHandler      libclickhouse_interpreters.so                        [.] DB::UserDefinedSQLFunctionMatcher::visit                                                                                                       ▒
   - 0.82% DB::UserDefinedSQLFunctionMatcher::visit                                                                                                                                                                                                         ▒
      - 0.79% DB::UserDefinedSQLFunctionMatcher::tryToReplaceFunction                                                                                                                                                                                       ▒
           0.69% DB::UserDefinedSQLFunctionFactory::tryGet

It doesn't make sense to pay for this visitor if you are not using UDFs.

[kitaisreal]

@Algunenano why we make it as draft, it seems that change is small and well isolated we can merge it.

[Algunenano]

Sorry, but once you create a draft MR the default changes and any new PR is open as draft if you don't change it back.