Added data URL support for node.js; (#4725)

* Added data URL support for node.js;
Added missed data URL protocol for the browser environment;
Optimized JSON parsing in the default response transformer;
Refactored project structure;
Added `cause` prop for AxiosError instance that refers to the original error if it was wrapped with `AxiosError.from` method;
Added fromDataURI helper;
Added test for handling data:url as an `arraybuffer|text|stream`;

* Added throwing of 405 HTTP error if the method is not GET;

lib/utils.js

@@ -229,15 +229,16 @@ function trim(str) {
  *  navigator.product -> 'NativeScript' or 'NS'
  */
 function isStandardBrowserEnv() {
-  if (typeof navigator !== 'undefined' && (navigator.product === 'ReactNative' ||
-                                           navigator.product === 'NativeScript' ||
-                                           navigator.product === 'NS')) {
+  var product;
+  if (typeof navigator !== 'undefined' && (
+    (product = navigator.product) === 'ReactNative' ||
+    product === 'NativeScript' ||
+    product === 'NS')
+  ) {
     return false;
   }
-  return (
-    typeof window !== 'undefined' &&
-    typeof document !== 'undefined'
-  );
+
+  return typeof window !== 'undefined' && typeof document !== 'undefined';
 }
 
 /**