api: support threefold login tokens

[maxux]

Support threefold login app to authenticate and create token valid for api calls.

Internal changes:

• Each protected url now use security modules, this module does the selection between iyo and threebot.
• Still use Authorization: bearer [token] as authentication method, both supported and detected
• Generate a persistant token based on a single login via the app
• Generated token is signed by private key of the hub, and verified when used to ensure it's issued by the hub
• Add a new interface page to show token and example how to use it

Available for test: https://playground.hub.grid.tf/