add submissions dashboard view

app/javascript/elements/toggle_cookies.js

@@ -0,0 +1,17 @@
+export default class extends HTMLElement {
+  connectedCallback () {
+    this.button.addEventListener('click', () => {
+      const expirationDate = new Date()
+
+      expirationDate.setFullYear(expirationDate.getFullYear() + 10)
+
+      const expires = expirationDate.toUTCString()
+
+      document.cookie = this.dataset.key + '=' + this.dataset.value + '; expires=' + expires + '; path=/'
+    })
+  }
+
+  get button () {
+    return this.querySelector('button')
+  }
+}