DMC-1396: Get storage-issued tokens with OAuth2 flow if standard macaroons retrieval fails
This is my minimal effort attempt to try to solve the different behavior of StoRM GGUS-Ticket-ID: #164032 when it comes to retrieve a macaroon tokens for HTTP TPC.
This merge request does not modify the TokenRetriever
class or any of it's sub-classes. It simply initializes the "token retriever" chain with two MacaroonRetriever
objects; One initialized without any issuer (same as before) and a second one where the storage endpoint url is provided as the issuer when initializing the MacaroonRetriever
class.