feat(router-store): add @nrwl/angular data persistence operators (#3841)

Closes #3777

Author: brandonroberts

modules/router-store/.eslintrc.json

@@ -1,6 +1,12 @@
 {
   "extends": ["../../.eslintrc.json"],
-  "ignorePatterns": ["!**/*", "schematics-core"],
+  "ignorePatterns": [
+    "!**/*",
+    "schematics-core",
+    "data-persistence/src/public_api.ts",
+    "data-persistence/src/operators.ts",
+    "data-persistence/index.ts"
+  ],
   "overrides": [
     {
       "files": ["*.ts"],

modules/router-store/data-persistence/index.ts

@@ -0,0 +1,6 @@
+export {
+  fetch,
+  navigation,
+  optimisticUpdate,
+  pessimisticUpdate,
+} from './src/operators';

modules/router-store/data-persistence/ng-package.json

@@ -0,0 +1 @@
+{}