lagging a bit behind on terrain. Which is fine. Block Places and Block Pickup are not handled in this stream, as they go through the standart route of event handling.
- Separate `invite` machinery from `group_manip` into it's own thing (includes renaming `group_invite` to `invite` where applicable).
- Move some invite/trade machinery to `ControlEvent`.
- Make `TradePhase` a proper enum instead of a bunch of bools.
- Make `TradeId` a proper newtype.
- Remove trades from `Trades` on accept (previously was only on decline).
- Typo fixes/misc cleanup.
- Add bullet point for trading to the changelog.
- Fix item swapping edge case
- Document more assumptions/edge cases
- fmt and clippy
- s/ServerGeneral::GroupInvite/ServerGeneral::Invite/
- Use `Client::current` in `Client::is_dead`