* Handle relative urls for oauth authorization

The full URL is computed based on the current selected server
if a relative URL is used as authorizationUrl
or tokenUrl
Co-authored-by: NEliot Berriot <contact@eliotberriot.com>

* Add default configuration `preserveAuthorization`

* Add localStorage to auth plugin

* Add persistAuthorization unit tests

* Refactor persistAuthorization to use wrapped actions

* Upgrade unit tests to be compatible with jest

* Add persistAuthorization documentation
Co-authored-by: NTim Lai <timothy.lai@gmail.com>

* Add PKCE support.

* Fix tests

* Update oauth2.md

* Rename usePkce

* Fix the BrokenComponent error

* Update oauth2.md

* Remove isCode variable. Remove uuid4 dependency.

* Remove utils functions

* Import crypto

* Fix tests

* Fix the tests

* Cleanup

* Fix code_challenge generation

* Move code challenge and verifier to utils for mocks. Update tests.

* Mock the PKCE methods in the utils file properly.

* Add missing expect

* use target-method spies

* Add comments to explain test values.

* Get rid of jsrsasign.

* create `features` folder

* add base oauth2 server

* continue implementing OAuth tests

* WIP

* add password flow tests

* modify Password flow credential types

* remove query string credential type

* add test case for Authorization flow

* add specific Authorization value for Password flow test

* WIP

* fix linter issues

* Additional fix of #4048, more error messages from authorization call
  Inspect the error and error_description properties of the response, if available
* Fixed linter errors

* tests: add failing unit tests

* fix: add additionalQueryStringParams to auth requests

* 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.

fix filed name for scope of grant request body.

since that is technically correct

Added authorizeAccessCodeWithBasicAuthentication() that sends the client_id and
client_secret using HTTP basic authentication

    Authorization: Basic base64encoded[client_id:client_secret]

According to the OAuth2 spec, this is the preferred method.  It also enables
Authorization Servers that only support basic authentication during the
authorization_code grant.

https://tools.ietf.org/html/rfc6749#section-2.3.1

also fix indentations of files

add configuration of auth: scope separator, client id, client secret, app name, reaml, additionalQueryParams