fix: use abort-controller pkg for node <15

package.json

@@ -74,6 +74,7 @@
   },
   "dependencies": {
     "@babel/runtime-corejs3": "^7.17.2",
+    "abort-controller": "^3.0.0",
     "bs58": "^4.0.1",
     "clone": "^2.1.2",
     "core-js": "^3.21.0",

src/baseRequest.js

@@ -2,6 +2,8 @@
 // SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
 // Code is Apache-2.0 and docs are CC-BY-4.0
 
+// TODO: remove abort-controller when using Node >=15
+import AbortController from 'abort-controller'
 import { Promise } from 'es6-promise'
 import fetchPonyfill from 'fetch-ponyfill'
 import { vsprintf } from 'sprintf-js'