fix: resolve @angular/language-service from root node_module

All dependencies are now listed in root node_modules, so we should not
resolve `@angular/language-service` from `server`.

Author: kyliau

client/src/extension.ts

@@ -145,7 +145,7 @@ function constructArgs(ctx: vscode.ExtensionContext, debug: boolean): string[] {
   }
 
   const ngdk: string|null = config.get('angular.ngdk', null);
-  const ngProbeLocations = getProbeLocations(ngdk, ctx.asAbsolutePath('server'));
+  const ngProbeLocations = getProbeLocations(ngdk, ctx.extensionPath);
   args.push('--ngProbeLocations', ngProbeLocations.join(','));
 
   const experimentalIvy: boolean = config.get('angular.experimental-ivy', false);