support zstd compressor for grpc

[ssesha]

Is your feature request related to a problem? Please describe.
Inter AZ network costs between distributor and ingesters are a major issue faced by all. Currently one way to bring the network costs down is to enable gzip compression on grpc calls between distributors and ingesters

Describe the solution you'd like
with a pure go implementation of zstd now available, we can look at trying out zstd compression as an alternative to gzip.