[clang-tools-extra] [clangd] Support .clangd command line modifications for C++ modules (PR #122606)

[Petr Polezhaev via cfe-commits]

petr-polezhaev wrote:

Didn't knew that's a thing now. Removed the checkbox over the private email, should be ok now. Somehow missed the clang-format issue again (I thought I fixed it) - updated to calm it down

https://github.com/llvm/llvm-project/pull/122606