zstd is not added to cmake or fbcode builder manifests

[fredemmott]

Repro:

os_image=ubuntu:18.04 gcc_version=7 make_parallelism=5 travis_cache_dir=~/travis_ccache \
  build/fbcode_builder/travis_docker_build.sh

The dockerized build fails for a few reasons:

1. the dependency is not declared in the manifests, so the header files are unavailable
2. zstd was never added to fizz's cmake, so building the shared object fails

On github actions, (1) is not an issue because of a different dependency installation order/process, and (2) is not an issue because zstd is built a static library, so undefined symbol errors are delayed.

While Travis isn't supported any more, being able to build a docker image is still useful, and fizz should handle zstd in CMake regardless.

[mingtaoy]

This was fixed in 32ad80d and 38cefa8