refactor(contracts): Standardize WZETA contract version

contracts/shared/WZETA.sol

@@ -1,4 +1,5 @@
-pragma solidity ^0.4.18;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
 
 contract WZETA {
     string public name = "Wrapped Zeta";
@@ -13,29 +14,29 @@ contract WZETA {
     mapping(address => uint) public balanceOf;
     mapping(address => mapping(address => uint)) public allowance;
 
-    function() public payable {
+    receive() external payable {
         deposit();
     }
 
     function deposit() public payable {
         balanceOf[msg.sender] += msg.value;
-        Deposit(msg.sender, msg.value);
+        emit Deposit(msg.sender, msg.value);
     }
 
     function withdraw(uint wad) public {
         require(balanceOf[msg.sender] >= wad);
         balanceOf[msg.sender] -= wad;
-        msg.sender.transfer(wad);
-        Withdrawal(msg.sender, wad);
+        payable(msg.sender).transfer(wad);
+        emit Withdrawal(msg.sender, wad);
     }
 
     function totalSupply() public view returns (uint) {
-        return this.balance;
+        return address(this).balance;
     }
 
     function approve(address guy, uint wad) public returns (bool) {
         allowance[msg.sender][guy] = wad;
-        Approval(msg.sender, guy, wad);
+        emit Approval(msg.sender, guy, wad);
         return true;
     }
 
@@ -46,20 +47,20 @@ contract WZETA {
     function transferFrom(
         address src,
         address dst,
-        uint wad
+        uint256 wad
     ) public returns (bool) {
         require(balanceOf[src] >= wad);
 
-        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
+        if (src != msg.sender && allowance[src][msg.sender] != type(uint256).max) {
             require(allowance[src][msg.sender] >= wad);
             allowance[src][msg.sender] -= wad;
         }
 
         balanceOf[src] -= wad;
         balanceOf[dst] += wad;
 
-        Transfer(src, dst, wad);
+        emit Transfer(src, dst, wad);
 
         return true;
     }
-}
+}

hardhat.config.ts

@@ -16,7 +16,6 @@ const config: HardhatUserConfig = {
       { version: "0.8.7" },
       { version: "0.5.10" /** For create2 factory */ },
       { version: "0.5.16" /** For uniswap v2 core*/ },
-      { version: "0.4.19" /** For weth*/ },
     ],
   },
 };

typechain-types/@openzeppelin/contracts/index.ts

@@ -1,7 +1,5 @@
 /* Autogenerated file. Do not edit manually. */
 /* tslint:disable */
 /* eslint-disable */
-import type * as access from "./access";
-export type { access };
 import type * as token from "./token";
 export type { token };

typechain-types/@zetachain/protocol-contracts/contracts/evm/index.ts

@@ -3,5 +3,3 @@
 /* eslint-disable */
 import type * as interfaces from "./interfaces";
 export type { interfaces };
-import type * as tools from "./tools";
-export type { tools };

typechain-types/@zetachain/protocol-contracts/contracts/evm/interfaces/index.ts

@@ -3,4 +3,3 @@
 /* eslint-disable */
 import type * as zetaInterfacesSol from "./ZetaInterfaces.sol";
 export type { zetaInterfacesSol };
-export type { ZetaInteractorErrors } from "./ZetaInteractorErrors";