Fail fast if codeql CLI is missing from the workspace

In order to run our cli-integration tests, we're required to have a
local copy of the codeql CLI repo. We can then run the tests by running
the `Launch Integration Tests - With CLI` task from inside VS Code.

(See CONTRIBUTING.md for details.)

If we don't have the CLI repo cloned locally or we're not pointing to it
in `launch.json`, we don't get a clear indication of what the problem is.

The tests will still attempt to run.

Let's fail fast instead and add an actionable error message to the output.

Author: elenatanasoiu

extensions/ql-vscode/src/vscode-tests/cli-integration/global.helper.ts

@@ -75,7 +75,7 @@ export default function(mocha: Mocha) {
     }
   );
 
-  // ensure etension is cleaned up.
+  // ensure extension is cleaned up.
   (mocha.options as any).globalTeardown.push(
     async () => {
       const extension = await extensions.getExtension<CodeQLExtensionInterface | Record<string, never>>('GitHub.vscode-codeql')!.activate();
@@ -93,6 +93,21 @@ export default function(mocha: Mocha) {
       removeStorage?.();
     }
   );
+
+  // check that the codeql folder is found in the workspace
+  (mocha.options as any).globalSetup.push(
+    async () => {
+      const folders = workspace.workspaceFolders;
+      if (!folders) {
+        fail('\n\n\nNo workspace folders found.\nYou will need a local copy of the codeql repo.\nMake sure you specify the path to it in launch.json.\nIt should be something along the lines of "${workspaceRoot}/../codeql" depending on where you have your local copy of the codeql repo.\n\n\n');
+      } else {
+        const codeqlFolder = folders.find(folder => folder.name === 'codeql');
+        if (!codeqlFolder) {
+          fail('\n\n\nNo workspace folders found.\nYou will need a local copy of the codeql repo.\nMake sure you specify the path to it in launch.json.\nIt should be something along the lines of "${workspaceRoot}/../codeql" depending on where you have your local copy of the codeql repo.\n\n\n');
+        }
+      }
+    }
+  );
 }
 
 export async function cleanDatabases(databaseManager: DatabaseManager) {