[clang-tools-extra] [clangd] Don't offer Extract to Function for control-flow conditions (PR #223409)

[Christian Kandeler via cfe-commits]

ckandeler wrote:

> Can you please replace `condition/init/increment` with `condition` in the PR description?
> 
> I found that we have a problem with `if (auto A = [[func()]])`, but seem this is not control-flow related because can be reproduced with simple `auto A = [[func()]];`, thus it's more general problem produced by #219945. So, I think it's ok to keep this behavior as this in this PR, but we need another PR to address this problem (or maybe you can fix all the problems here, it's up to you).

I have updated the description and will handle the other problem in a dedicated PR.

https://github.com/llvm/llvm-project/pull/223409