feat: Add UI to switch teams where signed in to multiple (#2457)

* feat: Add UI to switch teams where signed in to multiple

* fix: Do not display current team in switch menu

* Refactor to hook

app/hooks/useSessions.js

@@ -0,0 +1,29 @@
+// @flow
+import * as React from "react";
+import { getCookie } from "tiny-cookie";
+
+type Session = {|
+  url: string,
+  logoUrl: string,
+  name: string,
+  teamId: string,
+|};
+
+function loadSessionsFromCookie(): Session[] {
+  const sessions = JSON.parse(getCookie("sessions") || "{}");
+
+  return Object.keys(sessions).map((teamId) => ({
+    teamId,
+    ...sessions[teamId],
+  }));
+}
+
+export default function useSessions() {
+  const [sessions, setSessions] = React.useState(loadSessionsFromCookie);
+
+  const reload = React.useCallback(() => {
+    setSessions(loadSessionsFromCookie());
+  }, []);
+
+  return [sessions, reload];
+}