3lang: nostr: define actions and implement for nostr

[brandonpille]

We should be able to support high level nostr functionality through 3lang:

• sending a message
• creating a group (channel)
• list the existing groups (channels)
• subscribe to groups
• pull the messages from a channel (events)

Todo:

• [ ] define the actions that we need to support functionality of nostr (in md book)
• [ ] implementation to parse the actions
• [ ] call the right api client function for each action

Things like loading key, getting the id, getting public key, should happen automatically when needed