Currently clang-tools' derivation uses a hardcoded list of names to
distinguish between what's a compiler-like binary and what's a tool-like
binary (so that e.g. clang-tidy is included in the derivation, but
clang-13 - not).
Because Clang's tools follow a common naming convention
(clang-somethingsomething), I think it's easier if we just used a simple
regular expression in place of the hardcoded list.
Creates and installs wrapper scripts around the clang-tools from
`llvmPackages.clang-unwrapped`.
Motivation
----------
Fixes#9214
Allows to install clang-tools for C++ development without also installing the
clang compiler and its tool-chain. This way it is possible to use e.g.
`clang-format` without conflicting with e.g. GCC's tool-chain, or the global
system tool-chain.
