Update TypeScript lib target to es2020 on schematics

Author: fahrigedik

npm/ng-packs/packages/schematics/src/commands/create-lib/files-package-standalone/__libraryName@kebab__/tsconfig.lib.json.template

@@ -10,7 +10,7 @@
     "types": [],
     "lib": [
       "dom",
-      "es2018"
+      "es2020"
     ]
   },
   "exclude": [

npm/ng-packs/packages/schematics/src/commands/create-lib/files-package/__libraryName@kebab__/tsconfig.lib.json.template

@@ -10,7 +10,7 @@
     "types": [],
     "lib": [
       "dom",
-      "es2018"
+      "es2020"
     ]
   },
   "exclude": [

npm/ng-packs/packages/schematics/tsconfig.json

@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
     "baseUrl": "tsconfig",
-    "lib": ["es2019", "dom"],
+    "lib": ["es2020", "dom"],
     "declaration": true,
     "module": "commonjs",
     "moduleResolution": "node",