fix: go back to user selection from other user (#6255)

* fix: go back to user selection from other user

* fix: replace button with left arrow

internal/api/ui/login/static/resources/scripts/go_back.js

@@ -0,0 +1,12 @@
+document.getElementById("back-button").addEventListener("click", goBack);
+document.getElementById("back-button").style.visibility = wereInUserSelection()
+  ? "visible"
+  : "hidden";
+
+function goBack() {
+  history.back();
+}
+
+function wereInUserSelection() {
+  return window.location.href.includes("userselection");
+}