feat: add skeleton solidity test plugin

This is based on the `@ignored/edr` version that comes from the Solidity
Test branch of EDR.

We create a skeleton `solidity-test` plugin, that leverages the
artifacts manager to find contracts and test contracts and pass them off
to the EDR Solidity Test Runner before displaying the results.

v-next/example-project/contracts/Counter.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract Counter {
+  uint public x;
+
+  function inc() public {
+    x++;
+  }
+}

v-next/example-project/contracts/Counter.t.sol

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "./Counter.sol";
+
+contract CounterTest {
+  Counter counter;
+
+  function setUp() public {
+    counter = new Counter();
+  }
+
+  function testInitialValue() public view {
+    require(counter.x() == 0, "Initial value should be 0");
+  }
+
+  function testInc() public {
+    counter.inc();
+    require(counter.x() == 1, "Value after inc should be 1");
+  }
+}

v-next/hardhat-errors/src/descriptors.ts

@@ -73,6 +73,11 @@ export const ERROR_CATEGORIES: {
     max: 999,
     websiteTitle: "Network-helpers errors",
   },
+  SOLIDITY_TESTS: {
+    min: 1000,
+    max: 1099,
+    websiteTitle: "Solidity tests errors",
+  },
 };
 
 export const ERRORS = {
@@ -685,4 +690,12 @@ This might be caused by using hardhat_reset and loadFixture calls in a testcase.
       websiteDescription: "Error while reverting snapshot",
     },
   },
+  SOLIDITY_TESTS: {
+    BUILD_INFO_NOT_FOUND_FOR_CONTRACT: {
+      number: 1000,
+      messageTemplate: `Build info not found for contract {fqn}`,
+      websiteTitle: `Build info not found for contract`,
+      websiteDescription: `Build info not found for contract while compiling Solidity test contracts.`,
+    },
+  },
 } as const;

v-next/hardhat/package.json

@@ -77,6 +77,7 @@
     "typescript-eslint": "7.7.1"
   },
   "dependencies": {
+    "@ignored/edr": "0.6.2-alpha.0",
     "@ignored/hardhat-vnext-build-system": "workspace:^3.0.0-next.2",
     "@ignored/hardhat-vnext-errors": "workspace:^3.0.0-next.2",
     "@ignored/hardhat-vnext-utils": "workspace:^3.0.0-next.2",