[Config] Enable gRPC listen endpoint and client connetion

[red-0ne]

Objective

With the current setup, Pocket nodes are not exposing any gRPC port that lets clients such as POKTRollSDK, AppGateServer or RelayMiner connect to it using a simple gRPC client.

This makes these clients require a cosmosclient.Context dependency which forces us to run them as a CosmosSDK standalone binary which is a blocker for POKTRollDSK to run as an importable library that other project could use in their own codebase.

Origin Document

pokt-network/helm-charts#15 (comment)

Goals

• Prevent the SDK from being dependent on CosmosSDK's context (cosmostclient.Context)
• Enable gRPC communication with Pocket nodes (poktrolld)
• Be able to import the SDK without running its logic as an external binary and resorting to an HTTP server as a mean to interact with it.
• Enable SDK to use gRPC while keeping the regular RPC client for event subscriptions.

Deliverables

• Update helm-charts to enable and expose --grpc.addr helm-charts/pull/16.
• Refactor POKTRollSDK to use grpc.ClientConn to talk to Pocket nodes [SDK] feat: Have distinct JSON-RPC and gRPC urls #261
• Refactor AppGateServer and RelayMiner to use a gRPC client instead of cosmos client
  • Add FlagGRPC to their respective cmd.go commands
  • Adapt the config files to use a Websocket client for event subscriptions via query_node_rpc_url
  • Adapt the config files to use gRPC clients for queries (query_node_grpc_url) and sending transactions (tx_node_grpc_url) [Configs] Add foundation for RelayMiner operation configs. #284
• Update helm-charts to reflect the changes made to AppGateServer and RelayMiner config files helm-charts/pull/15.

Non-goals / Non-deliverables

• Update the E2E tests to use gRPC to communicate with Pocket nodes.
• Update poktrolld tx commands to use gRPC to submit transactions to Pocket nodes.

Creator: @red-0ne
Co-Owners: @Olshansk , @bryanchriswhite

[red-0ne]

Closed by #284