Clear pack cache on create and delete

We were only clearing the pack cache when a pack file was modified. When
using a script to create a new pack, the pack file is created at once
without a change event firing. This will change the behavior to also
clear the pack cache when a pack file is created or deleted.

extensions/ql-vscode/src/extension.ts

@@ -707,9 +707,14 @@ async function activateWithInstalledDistribution(
   for (const glob of PACK_GLOBS) {
     const fsWatcher = workspace.createFileSystemWatcher(glob);
     ctx.subscriptions.push(fsWatcher);
-    fsWatcher.onDidChange(async (_uri) => {
+
+    const clearPackCache = async (_uri: Uri) => {
       await qs.clearPackCache();
-    });
+    };
+
+    fsWatcher.onDidCreate(clearPackCache);
+    fsWatcher.onDidChange(clearPackCache);
+    fsWatcher.onDidDelete(clearPackCache);
   }
 
   void extLogger.log("Initializing database manager.");