Sharing support for clang-tidy (and maybe more) with other repositories

Sharing support for clang-tidy (and maybe more) with other repositories

*Description*:
The envoy-perf repository now runs clang-tidy in CI [1]. In order to so,
some scripts had to be copied over from Envoy, resulting in code duplication.
This was needed because some minor changes were required.
It would be nice to have unified support for things like clang-format, perhaps via a
shared submodule.

*Links*:
[[1] Envoy-perf pull request introducing clang-tidy in CI](https://github.com/envoyproxy/envoy-perf/pull/44
)