FederationRestrictions: make RestrictedInstance function like an accordion

app/styles/components/federation-restrictions.scss

@@ -3,9 +3,55 @@
 }
 
 .restricted-instance {
-  padding: 10px 0;
+  &__header {
+    padding: 10px 0;
+    display: flex;
+    text-decoration: none;
+    color: var(--primary-text-color);
+  }
 
-  &--reject {
+  &__icon {
+    width: 16px;
+  }
+
+  &--expanded &__icon i.fa {
+    transform: translateX(-3px);
+  }
+
+  &--reject &__host {
     text-decoration: line-through;
   }
+
+  &__restrictions {
+    height: 0;
+    overflow: hidden;
+  }
+
+  &--expanded &__restrictions {
+    height: auto;
+  }
+
+  .instance-restrictions {
+    padding: 5px 0 5px 15px;
+    border-left: 3px solid hsla(var(--primary-text-color_hsl), 0.4);
+    color: var(--primary-text-color--faint);
+    margin-bottom: 15px;
+
+    .federation-restriction {
+      padding: 7px 0;
+      font-size: 14px;
+    }
+
+    &__message {
+      margin-bottom: 10px;
+
+      i.fa {
+        padding-right: 10px;
+      }
+
+      &:last-child {
+        margin-bottom: 0;
+      }
+    }
+  }
 }