feat: implement External system (API) controller with key management

frontend/app/types/api_keys.ts

@@ -0,0 +1,11 @@
+export type ApiKey = {
+    id: number,
+    name: string,
+    created_at: string,
+    last_used_at: string,
+    owner: string,
+};
+
+export type NewApiKey = {
+    key: string,
+};