* create group
* add user as member, store methods to get group and to create group member
* add group member and send member invitation
* fix ci: use simplexmq from github
* chat protocol: create SMP agent connection when inviting member
* update protocol, started group invitation receiving
* chat types, chat protocol syntax idea
* chat message syntax, raw message type
* chat message format and parsing
* raw chat message parsing test
* add message parsing tests
* interpret RawChatMessage
* use chat message format when sending messages
* save contacts and related connections to DB (WIP)
* use contacts in all chat commands (add, connect, send, delete)
* use contacts when receiving messages and notifications
* handle contact not found error
* automatically accept connection when CONF is received from the agent
