Keep temporary context on reload
Some context field like company or employee are designed to be kept per client session even on context reload. But #3837 (closed) removed this behavior globally for any context reload. But instead it is when the user modify his preferences that we must reload cleanly the context.
Also on sao we keep the session in the browser so reloading the page keep us logged. But sao fetch a new context which may change the "session" fields like company or employee. I propose to store in the sessionStorage those values and restore them on reload. The sessionStorage is kept only per tab so it is not shared between tabs and it is cleared when the tab is closed. This means that a user could have two tabs opened on the same server and changed his preferences on one (change company or employee) and he can reload each tab without loosing each context.