Deploy plugins asynchronously (#13134)

- Make `initialize` method in `PluginDeployerContribution` sync to  continue with backend loading while plugins are deployed
- Fix wrong performance measurements of `resolvePlugins` & `deployPlugins` &  in `PluginDeployerImpl`
- Improve performance logging in `HostedPluginSupport` by only logging relevent measurements of `sync/`load` and `start` plugins 
  (i.e. if the plugin count is 0 just stop the measurement but don`t log)
- Update `I18nPreloadContribution` to ensure that we only load the localizations from the backend if the current locale is not equal to the default locale

packages/core/src/browser/preload/i18n-preload-contribution.ts

@@ -33,7 +33,7 @@ export class I18nPreloadContribution implements PreloadContribution {
                 locale: defaultLocale
             });
         }
-        if (nls.locale) {
+        if (nls.locale && nls.locale !== nls.defaultLocale) {
             const localization = await this.localizationServer.loadLocalization(nls.locale);
             if (localization.languagePack) {
                 nls.localization = localization;

packages/plugin-ext/src/hosted/browser/hosted-plugin.ts

@@ -401,8 +401,12 @@ export class HostedPluginSupport {
                 waitPluginsMeasurement.error('Backend deployment failed.');
             }
         }
-
-        syncPluginsMeasurement?.log(`Sync of ${this.getPluginCount(initialized)}`);
+        if (initialized > 0) {
+            // Only log sync measurement if there are were plugins to sync.
+            syncPluginsMeasurement?.log(`Sync of ${this.getPluginCount(initialized)}`);
+        } else {
+            syncPluginsMeasurement.stop();
+        }
     }
 
     /**
@@ -440,8 +444,12 @@ export class HostedPluginSupport {
                 }));
             }
         }
-
-        loadPluginsMeasurement.log(`Load contributions of ${this.getPluginCount(loaded)}`);
+        if (loaded > 0) {
+            // Only log load measurement if there are were plugins to load.
+            loadPluginsMeasurement?.log(`Load contributions of ${this.getPluginCount(loaded)}`);
+        } else {
+            loadPluginsMeasurement.stop();
+        }
 
         return hostContributions;
     }
@@ -512,7 +520,11 @@ export class HostedPluginSupport {
             return;
         }
 
-        startPluginsMeasurement.log(`Start of ${this.getPluginCount(started)}`);
+        if (started > 0) {
+            startPluginsMeasurement.log(`Start of ${this.getPluginCount(started)}`);
+        } else {
+            startPluginsMeasurement.stop();
+        }
     }
 
     protected async obtainManager(host: string, hostContributions: PluginContributions[], toDisconnect: DisposableCollection): Promise<PluginManagerExt | undefined> {

packages/plugin-ext/src/main/node/plugin-deployer-contribution.ts

@@ -28,7 +28,7 @@ export class PluginDeployerContribution implements BackendApplicationContributio
     @inject(PluginDeployer)
     protected pluginDeployer: PluginDeployer;
 
-    initialize(): Promise<void> {
-        return this.pluginDeployer.start();
+    initialize(): void {
+        this.pluginDeployer.start().catch(error => this.logger.error('Initializing plugin deployer failed.', error));
     }
 }

packages/plugin-ext/src/main/node/plugin-deployer-impl.ts

@@ -130,8 +130,9 @@ export class PluginDeployerImpl implements PluginDeployer {
             id,
             type: PluginType.System
         }));
+        const resolvePlugins = this.measure('resolvePlugins');
         const plugins = await this.resolvePlugins([...unresolvedUserEntries, ...unresolvedSystemEntries]);
-        deployPlugins.log('Resolve plugins list');
+        resolvePlugins.log('Resolve plugins list');
         await this.deployPlugins(plugins);
         deployPlugins.log('Deploy plugins list');
     }