Merged in feat/sw-2403-mystay-webview (pull request #1828)

Feat/sw-2403 - Adding webview for MyStay

* feat/webview - added for my stay

* wip

* Passing headers so we can get the lang

* Cleanup

* Refactored and some performance improvements


Approved-by: Christian Andolf

apps/scandic-web/app/[lang]/webview/hotelreservation/README.md

@@ -0,0 +1,27 @@
+# Booking flow
+
+The booking flow is the user journey of booking one or more rooms at our
+hotels. Everything from choosing the date to payment and confirmation is
+part of the booking flow.
+
+## Booking widget
+
+On most of the pages on the website we have a booking widget. This is where
+the user starts the booking flow, by filling the form and submit. If they
+entered a city as the destination they will land on the select hotel page
+and if they entered a specific hotel they will land on the select rate page.
+
+## Select hotel
+
+Lists available hotels based on the search criteria. When the user selects
+a hotel they land on the select rate page.
+
+## Select rate, room, breakfast etc
+
+This is a page with an accordion like design, but every accordion is handled
+as its own page with its own URL.
+
+## State management
+
+The state, like search parameters and selected alternatives, is kept
+throughout the booking flow in the URL.