Embed query string param is saved in url #2475
Description
When an embed url is created for iframes it contains the embed query string param. This param tells kibana to render in embed mode and works great. The problem is that it is saved in the lastUrl and causes problems when you go from a page with an embeded vis to a full instance of kibana in the same session/tab (pretty sure lastUrl is saved in sessionStorage).
Pretty sure the solution to this is not to save the lastUrl if kibana is embedded (which would prevent the other side-effect of overwriting your previous visualize state) but perhaps a more all-encompassing solution would be better.