Allow editing and resetting of all admin setting strings

app/javascript/controllers/settings/resettable_field_controller.js

@@ -0,0 +1,10 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+  static targets = [ "resetButton" ]
+
+  resetField () {
+    const inputEl = this.element.querySelector('input')
+    inputEl.value = inputEl.dataset.defaultValue
+  }
+}