Unable to open 'Explore' in new window from Grafana menu

Impact on the user: 

Unable to open Explore  panel and save the current page 

STR

1. open any dashboard in PMM
2. go to Details on the panel 
3. Click Control + click to Explore 

Expected result 

• Explore Dashboard opened in new  window and current one with Dashboard is useful too 

Given result

• 404 error. Url opened without "graph" part. Looks like some hardcode  

Note: If this s a bug in Grafana  - let's push this to upstream but fix in our version if possible