Implement support for NIP-42 AUTH and access control

[mleku]

an important element of the required features for this relay is to enable it to be used in a purely private environment - given a client that actually respects users relay choices...

for this, it is necessary that the relay has a private internal events storage and a class of access permission of administrator and user

the administrator will be able to push administration access control events to the relay which will alter the stored ACL that also needs to be implemented

so, a checklist:

• [x] NIP-42 access control to privileged events (mainly private messages and application specific data)
• [x] ACL data structure format and role definitions
• [x] create configuration file and load/save
• [ ] administrative CRUD event types
• [ ] implement actions in response to CRUD event types
• [ ] add this functionality to the CLI client
  • [ ] merge nak features into postr for this
• [ ] add enforcement code to the default filtering code for the relay to auth-wall the access to the relay according to the role definitions

[mleku]

relay now does not leak privileged events to third parties based on queries for privileged event types or open ended ones that don't specify event types

next task will be to complete the access control protocol, first with the admin event types

[mleku]

relay now has an option to allow public events with ACL enabled, and an option to enforce authentication for access to everything

tested and works to relay direct messages between to different users

the next task is to create special events that the relay interprets as commands to modify the ACL

[mleku]

this is fully done

running a pinned version of coracle with forced relay settings makes everything almost perfectly smooth