Decrease download update delay

3 seconds is a really long time to wait for downloads since a
significant percentage of downloads will complete within 3 seconds. This
changes the update delay to 500ms which should still give us good
performance, but also make the download feel more responsive.

extensions/ql-vscode/src/remote-queries/variant-analysis-manager.ts

@@ -68,7 +68,7 @@ export class VariantAnalysisManager
   implements VariantAnalysisViewManager<VariantAnalysisView>
 {
   private static readonly REPO_STATES_FILENAME = "repo_states.json";
-  private static readonly DOWNLOAD_PERCENTAGE_UPDATE_DELAY_MS = 3000;
+  private static readonly DOWNLOAD_PERCENTAGE_UPDATE_DELAY_MS = 500;
 
   private readonly _onVariantAnalysisAdded = this.push(
     new EventEmitter<VariantAnalysis>(),