[clang-tools-extra] [clangd] Make all calls to format::getStyle() go through getFormatStyleForFile() (PR #82948)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

(This patch is in preparation for a fix for https://github.com/clangd/clangd/issues/1384, which I haven't posted yet because I haven't figured out how to do stacked PRs yet. However, this patch seems independently useful and reviewable.)

https://github.com/llvm/llvm-project/pull/82948