feat(core): switch to native fetch API for all HTTP requests

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@apiclient.xyz/bunq",
-  "version": "4.1.3",
+  "version": "4.2.0",
   "private": false,
   "description": "A full-featured TypeScript/JavaScript client for the bunq API",
   "type": "module",
@@ -33,7 +33,6 @@
     "@push.rocks/smartfile": "^11.2.5",
     "@push.rocks/smartpath": "^5.0.18",
     "@push.rocks/smartpromise": "^4.2.3",
-    "@push.rocks/smartrequest": "^2.0.21",
     "@push.rocks/smarttime": "^4.0.54"
   },
   "files": [