Smartcontract prototype for Pay per month

[Igx22]

1. read and cleanup dstorage.sol
   I'm pretty sure there are a lot of bugs - but I did this to define a skeleton of what is needed
   and what datastructures I need
   https://github.com/ethereum-push-notification-service/epns-dstorage/tree/contract-1/contract

2. use this template project
   https://github.com/Belf33/Web3-hardhat-solidity-js-starter/blob/master/test/unit/FundMe.test.js
   we need hardhat, tests, testnet scripts etc...

3. more features:
   nsToShardToSNodeMap
   nsToShard

maps should be populated via bindSNodeToShard(namespace, shard)

every modification should emit a SNodeMapped(wallet, namespace, shard)

and it all should land into SNode/mysql/network_storage_layout

and eventually (when it's all perfect) copied to VNode/mysql/network_storage_layout

// the workflow
// 1 a dapp says (I want to add a new node, I have money, I have url for API calls)
// API = I've setup a complete VNode docker instance (SNode)
// 2 this SC emits NodeAdded
// 3 all VNode/SNode receive NodeAdded
// 4 they update network_storage_layout
// and / or  node_info