Automatically open dropdown when toggling

When the sidebar is collapsed and the user clicks on
the Labels button, the sidebar will now automatically
expand and show the labels dropdown.

This is consistent with how other fields like status work.

ee/app/assets/javascripts/integrations/jira/issues_show/components/sidebar/jira_issues_sidebar_root.vue

@@ -56,6 +56,11 @@ export default {
       default: () => [],
     },
   },
+  data() {
+    return {
+      isEditingLabels: false,
+    };
+  },
   computed: {
     assignee() {
       // Jira issues have at most 1 assignee
@@ -104,6 +109,19 @@ export default {
         );
       }
     },
+    onIssueLabelsClose() {
+      this.isEditingLabels = false;
+    },
+    onIssueLabelsToggle() {
+      this.expandSidebarAndOpenDropdown();
+      this.sidebarEl.addEventListener(
+        'transitionend',
+        () => {
+          this.isEditingLabels = true;
+        },
+        { once: true },
+      );
+    },
     onIssueLabelsUpdated(labels) {
       this.$emit('issue-labels-updated', labels);
     },
@@ -143,8 +161,11 @@ export default {
       :labels-filter-base-path="issuesListPath"
       :labels-filter-param="$options.labelsFilterParam"
       :labels-select-in-progress="isUpdatingLabels"
+      :is-editing="isEditingLabels"
       variant="sidebar"
       class="block labels js-labels-block"
+      @onDropdownClose="onIssueLabelsClose"
+      @toggleCollapse="onIssueLabelsToggle"
       @updateSelectedLabels="onIssueLabelsUpdated"
     >
       {{ __('None') }}