Fix: refactor booking flow search params
* wip: apply codemod and upgrade swc plugin
* wip: design-system to react 19, fix issues from async (search)params
* Prepare new parse function for booking flow search params
* Prepare serialize function for booking flow search params
* Improve handling of comma separated arrays
* Slightly refactor for readability
* Next abstracts URLSearchParams so handle the abstraction instead
* Refactor booking widget to use new search params parsing
* Rename search param functions
* Refactor select-hotel to use new search param parser
* Use new search params parser in select-rate and details
* Fix hotelId type
* Avoid passing down search params into BookingWidget components
* More updates to use new types instead of SearchParams<T>
* Remove types SelectHotelSearchParams and AlternativeSelectHotelSearchParams
* Fix parseBookingWidgetSearchParams return type
* Add error handling to booking search param parsers
* Fix modifyRateIndex handling in details page
* Clean up
* Refactor booking widget search param serializing to util function
* Move start page booking widget search param parsing to page
* Use new search param serializer in HandleErrorCallback
* Delete convertSearchParamsToObj & convertObjToSearchParams
Approved-by: Michael Zetterberg
