Add API base URL and refactor imports; streamline cache handling in hooks. Replaced the DBlink.js because having just one file handle the connection is better, matches other projects. Used dblink coz i didnt know how to do it with graeme's method... sorry!

src/components/API/API.js

@@ -1,3 +1,5 @@
+export const API_BASE_URL = 'http://localhost:3000';
+
 const API = {};
 
 API.get = (endpoint) => callFetch(endpoint, 'GET');