[Do not merge] Setup hardhat zksync plugin

.gitignore

@@ -7,7 +7,10 @@ artifacts/@openzeppelin
 artifacts/build-info
 build/
 scripts/reference-scripts
-cache*/
+cache/
+cache-zk/
+cache_hardhat-zk/
+cache_hardhat/
 coverage/
 dist/
 node_modules/
@@ -19,7 +22,7 @@ abi/
 contracts/abi/
 contracts/README.md
 artifacts/
-artifacts-*/
+artifacts-zk/
 artifacts_forge/
 contract_artifacts/
 

.gitmodules

@@ -46,12 +46,3 @@
 [submodule "lib/openzeppelin-contracts"]
 	path = lib/openzeppelin-contracts
 	url = https://github.com/OpenZeppelin/openzeppelin-contracts
-[submodule "lib/v3-periphery"]
-	path = lib/v3-periphery
-	url = https://github.com/uniswap/v3-periphery
-[submodule "lib/v3-core"]
-	path = lib/v3-core
-	url = https://github.com/uniswap/v3-core
-[submodule "lib/swap-router-contracts"]
-	path = lib/swap-router-contracts
-	url = https://github.com/Uniswap/swap-router-contracts

contracts/extension/plugin/Router.sol

@@ -70,7 +70,7 @@ abstract contract Router is Multicall, ERC165, IRouter {
         _delegate(_pluginAddress);
     }
 
-    receive() external payable {}
+    receive() external payable virtual {}
 
     function _delegate(address implementation) internal virtual {
         assembly {