Fix(auth): improper resolution of relative token urls (#4180)

* fix(auth): improper resolution of relative token urls

* revert cc58ba7 for OAS2

In OAS2, relative token URLs are resolved against the host that serves the specs.

src/core/plugins/auth/actions.js

@@ -1,3 +1,4 @@
+import parseUrl from "url-parse"
 import win from "core/window"
 import { btoa, buildFormData } from "core/utils"
 
@@ -139,13 +140,15 @@ export const authorizeAccessCodeWithBasicAuthentication = ( { auth, redirectUrl
   return authActions.authorizeRequest({body: buildFormData(form), name, url: schema.get("tokenUrl"), auth, headers})
 }
 
-export const authorizeRequest = ( data ) => ( { fn, getConfigs, authActions, errActions, authSelectors } ) => {
+export const authorizeRequest = ( data ) => ( { fn, getConfigs, authActions, errActions, oas3Selectors, specSelectors } ) => {
   let { body, query={}, headers={}, name, url, auth } = data
-  let { additionalQueryStringParams } = authSelectors.getConfigs() || {}
-  let fetchUrl = url
 
-  for (let key in additionalQueryStringParams) {
-    url += "&" + key + "=" + encodeURIComponent(additionalQueryStringParams[key])
+  let fetchUrl
+
+  if (specSelectors.isOAS3()) {
+    fetchUrl = parseUrl(url, oas3Selectors.selectedServer()).toString()
+  } else {
+    fetchUrl = parseUrl(url, specSelectors.url()).toString()
   }
 
   let _headers = Object.assign({