(core) Add behavioral and coaching call popups

Summary:
Adds a new category of popups that are shown dynamically when
certain parts of the UI are first rendered, and a free coaching
call popup that's shown to users on their site home page.

Test Plan: Browser tests.

Reviewers: jarek

Reviewed By: jarek

Differential Revision: https://phab.getgrist.com/D3706

app/client/components/ViewConfigTab.js

@@ -177,7 +177,8 @@ ViewConfigTab.prototype._buildLayoutDom = function() {
           dom.autoDispose(layoutEditorObs),
           dom.on('click', () => commands.allCommands.editLayout.run()),
           grainjsDom.hide(layoutEditorObs),
-          testId('detail-edit-layout')
+          grainjsDom.cls('behavioral-prompt-edit-card-layout'),
+          testId('detail-edit-layout'),
         )
       );
     }