Refactor dialogs, make it simple to add a new dialog to all views

ui/src/layout/AppBar.js

@@ -12,6 +12,7 @@ import ViewListIcon from '@material-ui/icons/ViewList'
 import InfoIcon from '@material-ui/icons/Info'
 import PersonIcon from '@material-ui/icons/Person'
 import SupervisorAccountIcon from '@material-ui/icons/SupervisorAccount'
+import { Dialogs } from '../dialogs/Dialogs'
 import { AboutDialog } from '../dialogs'
 import PersonalMenu from './PersonalMenu'
 import ActivityPanel from './ActivityPanel'
@@ -127,6 +128,7 @@ const CustomUserMenu = ({ onClick, ...rest }) => {
         <Divider />
         <AboutMenuItem />
       </UserMenu>
+      <Dialogs />
     </>
   )
 }