Add scitoken authentication to daemon

[marcmengel]

The data_dispatcher daemon should be configurable to use SciToken authentication when talking to FERRY, Rucio, etc. Probably separately configurable for those services.

[marcmengel]

After some review, data_dispatcher uses the rucio-clients and metacat client libraries to contact those services, which already support token authentication, so the only place we're using certs in the data_dispatcher daemon is in:

• class RucioListener in daemon.py
• The dcache stage interfaces
  We don't even call Ferry, we let the metacat daemon handle that for all of us.

[marcmengel]

So the RucioListener uses "stompy" to connect to the Rucio service; it looks like we can pass it flags to set headers; confusingly, however it has a headers= parameter which it ignores, but it looks like you can pass Name=value arguments to set headers.
so we could send an Authorization="Bearer df09df0d9fd0fd0..." parameter to pass the header. I think. https://github.com/imandr/stompymq/blob/main/stompy/client.py#L141

It looks like we could add an Authorization header to theaders for the dcache parts fairly straighforwardly, i.e. at
https://github.com/fermitools/data_dispatcher/blob/main/daemon/dcache.py#L38
https://github.com/fermitools/data_dispatcher/blob/main/daemon/dcache.py#L103
https://github.com/fermitools/data_dispatcher/blob/main/daemon/dcache.py#L195

[marcmengel]

https://github.com/fermitools/data_dispatcher/blob/main/daemon/wlcg.py#L39
https://github.com/fermitools/data_dispatcher/blob/main/daemon/wlcg.py#L79
https://github.com/fermitools/data_dispatcher/blob/main/daemon/wlcg.py#L102