Update from Mihai who's on holiday

My thoughts on the topic:

- The Gfal2 change to retrieve macaroons/SE-issued tokens (unofficial v2.19.1) proved able to do the job. Petr tested SRM + HTTP TPC transfers using this change and they worked

- FTS-devel-next is already configure to not request SE-issued tokens, delegating this responsibility entirely to Gfal2. This instance has had these changes since before the Christmas break

My next steps:

- Implement macaroon retrieval in Gfal2 instead of relying on "x509-scitokens-issuer-client" package (change agreed with Brian)

- Stream out some edge cases I found out during my testing

- Move the testing ground from FTS-devel-next to FTS-devel instance. This means the change will become part of the Gfal2 develop branch (and due for the next release). Same thing applies for FTS: I will port the change which allows configuring FTS whether to obtain macaroons itself or not (leaving Gfal2 to do it) to the develop branch