feat: add cheats to read/write binary files (#189)

Author: mds1

src/Vm.sol

@@ -119,13 +119,18 @@ interface Vm {
 
     // Reads the entire content of file to string, (path) => (data)
     function readFile(string calldata) external returns (string memory);
+    // Reads the entire content of file as binary. Path is relative to the project root. (path) => (data)
+    function readFileBinary(string calldata) external returns (bytes memory);
     // Get the path of the current project root
     function projectRoot() external returns (string memory);
     // Reads next line of file to string, (path) => (line)
     function readLine(string calldata) external returns (string memory);
     // Writes data to file, creating a file if it does not exist, and entirely replacing its contents if it does.
     // (path, data) => ()
     function writeFile(string calldata, string calldata) external;
+    // Writes binary data to a file, creating a file if it does not exist, and entirely replacing its contents if it does.
+    // Path is relative to the project root. (path, data) => ()
+    function writeFileBinary(string calldata, bytes calldata) external;
     // Writes line to file, creating a file if it does not exist.
     // (path, data) => ()
     function writeLine(string calldata, string calldata) external;