Restrict topic subscription from OPAL Client and topic events from OPAL Server

[orweis]

Started as a discussion in https://github.com/authorizon/opal/discussions/159

^{Originally posted by jyoussefzadeh October 19, 2021} From the documentation & previous discussions, I understand that a JWT token can be issued to authenticate the OPAL Clients connection to OPAL Server.
Is it also possible to restrict which OPAL_DATA_TOPICS can be subscribed to from that client?
For instance, if there is a single shared pool of OPAL Servers with hundreds of different OPAL Clients connected to it, we do not want one client to be able to subscribe to & fetch unauthorized information that belongs to another client.
On a similar vein, given some bearer token for calling OPAL Server APIs, is it possible to restrict which topics that token can publish an event to, using the /data/config API?
Also, is it possible to restrict access to different OPAL Server endpoints entirely?