fix(ui-devkit): Update scaffolding to use correct eslib (#1886)

Closes #1859

packages/ui-devkit/scaffold/tsconfig.json

@@ -18,7 +18,7 @@
     "allowSyntheticDefaultImports": true,
     "typeRoots": [],
     "lib": [
-      "es2017",
+      "es2019",
       "dom",
       "esnext.asynciterable"
     ]