[clangd] Add a symbol-name-based blacklist for rename.

Summary:
This patch adds a simple mechanism to disallow global rename
on std symbols. We might extend it to other symbols, e.g. protobuf.

Reviewers: kadircet

Subscribers: mgorny, ilya-biryukov, MaskRay, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73450