keep graph displayed when build is clicked so that multiple tabs can be opened from graph

Also show spinner on every new request to let the user know that new data is inbound

app/assets/javascripts/vue_pipelines_index/stage.js.es6

@@ -9,9 +9,24 @@
         spinner: '<span class="fa fa-spinner fa-spin"></span>',
       };
     },
-    props: ['stage', 'svgs', 'match'],
+    props: {
+      stage: {
+        type: Object,
+        required: true,
+      },
+      svgs: {
+        type: DOMStringMap,
+        required: true,
+      },
+      match: {
+        type: Function,
+        required: true,
+      },
+    },
     methods: {
       fetchBuilds(e) {
+        if (this.builds) this.builds = '';
+
         const areaExpanded = e.currentTarget.attributes['aria-expanded'];
 
         if (areaExpanded && (areaExpanded.textContent === 'true')) return null;
@@ -24,6 +39,9 @@
             return flash;
           });
       },
+      keepGraph(e) {
+        e.stopPropagation();
+      },
     },
     computed: {
       buildsOrSpinner() {
@@ -64,7 +82,7 @@
         <ul class="dropdown-menu mini-pipeline-graph-dropdown-menu js-builds-dropdown-container">
           <div class="arrow-up"></div>
           <div
-            @click=''
+            @click='keepGraph($event)'
             :class="dropdownClass"
             class="js-builds-dropdown-list scrollable-menu"
             v-html="buildsOrSpinner"