Some pages use relative links such as boards link at the home page.
Others use absolute url such as cards in boards' lists.
This commits goal is to allow for consistent use of relative
urls.
Origin relative URLs also helps decoupling Wekan from the infrastructure
it's deployed on. i.e if it's being served, it should work.
* Add logic to search for archived or all cards
* Add icons to board, swimlane and list titles to indicate if they are archived
* Update search instructions
