Replaced dashboard "Top members" widget with longer activity feed

refs https://github.com/TryGhost/Team/issues/1290

- when the activity feed labs flag is enabled
  - hide top members widget
  - increase number of events in activity widget from 5 to 10

ghost/admin/app/components/dashboard/latest-member-activity.hbs

@@ -6,7 +6,7 @@
             </h4>
         </h4>
         <div class="content">
-            {{#let (members-event-fetcher filter=(if (feature "membersActivityFeed") "type:-[email_delivered_event,email_opened_event,email_failed_event]") pageSize=5) as |eventsFetcher|}}
+            {{#let (members-event-fetcher filter=(if (feature "membersActivityFeed") "type:-[email_delivered_event,email_opened_event,email_failed_event]") pageSize=(if (feature "membersActivityFeed") 10 5)) as |eventsFetcher|}}
                 {{#if eventsFetcher.isLoading}}
                     Loading...
                 {{/if}}

ghost/admin/app/controllers/dashboard.js

@@ -184,6 +184,10 @@ export default class DashboardController extends Controller {
     }
 
     loadTopMembers() {
+        if (this.feature.membersActivityFeed) {
+            return;
+        }
+
         this.topMembersLoading = true;
         let query = {
             filter: 'email_open_rate:-null',

ghost/admin/app/templates/dashboard.hbs

@@ -231,6 +231,7 @@
 
         <section class="gh-dashboard-area members-activity">
             {{#if this.showMembersData}}
+                {{#unless (feature "membersActivityFeed")}}
                 {{#if this.topMembersData}}
                     <div class="gh-dashboard-box grey top-members">
                         <div class="gh-dashboard-header-container">
@@ -280,6 +281,7 @@
                         </div>
                     </div>
                 {{/if}}
+                {{/unless}}
 
                 <Dashboard::LatestMemberActivity />
             {{/if}}