Introduce basic cli/output-cache.ts module

src/cli/output-cache.ts

@@ -0,0 +1,17 @@
+import path from "path";
+
+import { getTemporaryDirectory } from "../actions-util";
+
+/**
+ * The name of the temporary file that backs the on-disk cache of
+ * CLI responses between workflow steps.
+ */
+const COMMAND_CACHE_FILENAME = "codeql-action-command-cache.json";
+
+/**
+ * Returns the path to the temporary file that backs the
+ * on-disk cache of CLI responses between workflow steps.
+ */
+function getCommandCacheFilePath(): string {
+  return path.join(getTemporaryDirectory(), COMMAND_CACHE_FILENAME);
+}