test: Add Solidity test case and fixture to TestRepoMapAllLanguages

tests/fixtures/languages/solidity/test.sol

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract SimpleStorage {
+    uint256 private value;
+    
+    event ValueChanged(uint256 newValue);
+    
+    constructor(uint256 initialValue) {
+        value = initialValue;
+    }
+    
+    function setValue(uint256 newValue) public {
+        value = newValue;
+        emit ValueChanged(newValue);
+    }
+    
+    function getValue() public view returns (uint256) {
+        return value;
+    }
+}