BoardEvent "ParticipantUpdated" sends too much information

[BenedictHomuth]

The problem

For now, when a user updates his appearance (avatar), name or gets promoted from participant to moderator, a "ParticipantUpdated" event is used to sync those changes on all currently connected boards.

This general logic is fine, but the amount of data sent through the network can be improved – and would also make the event less bloated.

Therefore the event should be split in two:

• One for the updates on a given board session (role, ready state, banned, etc.) – potentially "BoardSessionUpdated"
• One for the updates of the account itself (avatar, name, etc.) – potentially "UserUpdated"

Screenshots

Current event: