[CORL-498, CORL-495, CORL-539, CORL-496, CORL-494] Email Notifications Support & Framework (#2498)

* chore: renamed old templates

* feat: initial notifications support

* feat: email enhancements

* fix: linting

* feat: initial digesting beheviour

* feat: added notification configuration

* feat: added unsubscribe routes

* fix: fixed failing snapshots/tests bc random ids

* feat: adjusted the save beheviour, added tests

* feat: added tests

* feat: added staff replies

* feat: renamed E-Mail to Email

* feat: enhanced cron processing

* fix: linting + updating tests

* feat: enhanced cron context

* fix: added staff replies back in

package.json

@@ -170,6 +170,7 @@
     "@types/cookie": "^0.3.3",
     "@types/cookie-parser": "^1.4.1",
     "@types/cors": "^2.8.4",
+    "@types/cron": "^1.7.1",
     "@types/cross-spawn": "^6.0.0",
     "@types/dotenv": "^4.0.3",
     "@types/enzyme": "^3.1.15",
@@ -200,6 +201,7 @@
     "@types/node-fetch": "^2.3.3",
     "@types/nodemailer": "^4.6.2",
     "@types/nunjucks": "^3.1.1",
+    "@types/object-diff": "0.0.0",
     "@types/on-finished": "^2.3.1",
     "@types/passport": "^0.4.6",
     "@types/passport-facebook": "^2.1.8",
@@ -290,6 +292,7 @@
     "marked": "^0.6.0",
     "material-design-icons": "^3.0.1",
     "mini-css-extract-plugin": "^0.6.0",
+    "object-diff": "0.0.4",
     "postcss-advanced-variables": "^3.0.0",
     "postcss-css-variables": "^0.11.0",
     "postcss-flexbugs-fixes": "^4.1.0",