Data Structures and Contract Storage Setup for storage contract

[sshubhamagg]

1. Define contract state variables:

   address public owner;
   bool public paused;
   uint256 public registrationFee;
   address public feeCollector;

2. Define core data structures:

   struct ID {
       address primaryWallet;
       uint256 registrationTimestamp;
       address registrar;
   }
   

3. Define storage mappings:

   mapping(uint256 => ID) private ids;
   mapping(address => uint256) private primaryWalletToId;
   mapping(address => uint256) private secondaryWalletToId;
   mapping(address => bool) private registrars;