Implement gRPC interface.

[YoEight]

No description provided.

[YoEight]

Error I got with https://github.com/awakesecurity/gRPC-haskell

yoeight@rannoch:~/code/EventStoreDB-Client-Haskell$ stack build --fast
grpc-haskell-core> configure
grpc-haskell-core> Configuring grpc-haskell-core-0.0.0.0...
grpc-haskell-core> build
grpc-haskell-core> Preprocessing library for grpc-haskell-core-0.0.0.0..
grpc-haskell-core> c2hs: Errors during expansion of binding hooks:
grpc-haskell-core> 
grpc-haskell-core> src/Network/GRPC/Unsafe.chs:145: (column 7) [ERROR]  >>> Unknown identifier!
grpc-haskell-core>   Cannot find a definition for `grpc_shutdown_blocking' in the header file.
grpc-haskell-core> 
Progress 1/3

--  While building package grpc-haskell-core-0.0.0.0 (scroll up to its section to see the error) using:
      /home/yoeight/.stack/setup-exe-cache/x86_64-linux-tinfo6/Cabal-simple_mPHDZzAJ_3.0.1.0_ghc-8.8.2 --builddir=.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.0.1.0 build --ghc-options " -fdiagnostics-color=always"
    Process exited with code: ExitFailure 1

[YoEight]

The error is probably due to debian buster having 1.16. Current Haskell gRPC library requires 1.2 but isn't tested with newer version

https://packages.debian.org/source/buster/grpc

[YoEight]

Switched to https://github.com/haskell-grpc-native/http2-grpc-haskell for internal gRPC library. 100% Haskell, no C weirdness.

[YoEight]

Got a cross dependencies issue with both proto-lens 0.6 and 0.7