Keyvalue inmemory golang provider

This provider example is implements wrpc:keyvalue/store@0.2.0-draft.

Notable files

• main.go is a simple binary that sets up an errGroup to handle running the provider's primary requirements: executing as a standaline binary based on data received on stdin, handling RPC and connecting to a wasmCloud lattice.
• keyvalue.go implements the required functions to conform to wasi:keyvalue/store. If the functions as specified in the ./wit directory are not implemented, this provider will fail to build.