Improve forms, add helper buttons on add session form

games/static/js/add_edition.js

@@ -0,0 +1,29 @@
+/**
+ * @description Sync select field with input field until user focuses it.
+ * @param {HTMLSelectElement} sourceElementSelector
+ * @param {HTMLInputElement} targetElementSelector
+ */
+function syncSelectInputUntilChanged(
+  sourceElementSelector,
+  targetElementSelector
+) {
+  const sourceElement = document.querySelector(sourceElementSelector);
+  const targetElement = document.querySelector(targetElementSelector);
+  function sourceElementHandler(event) {
+    let selected = event.target.value;
+    let selectedValue = document.querySelector(
+      `#id_game option[value='${selected}']`
+    ).textContent;
+    targetElement.value = selectedValue;
+  }
+  function targetElementHandler(event) {
+    sourceElement.removeEventListener("change", sourceElementHandler);
+  }
+
+  sourceElement.addEventListener("change", sourceElementHandler);
+  targetElement.addEventListener("focus", targetElementHandler);
+}
+
+window.addEventListener("load", () => {
+  syncSelectInputUntilChanged("#id_game", "#id_name");
+});