GUI: add table/tourney chat to deck editor for draft/sideboard/construct

Current table/tourney chat is useless:
- waiting table chat hides on match/tourney started;
- tourney chat in another window/panel and users don't want to switch to it;

XMage chat engine supports multiple rooms (game, tourney, server lobby, etc). And it supports multiple clients (viewers) for same room too.

So the main idea:
- [ ] must have 3 shared chats for server lobby, table (same as tourney and waiting), match (same as game);
- [ ] history of chat messages must be restored after reconnect (#5562);
- [ ] must support multiple instances of the same chat;
- [ ] deck editor must show table chat;
- [ ] optional: show game and table chats in the same window (its can be hard to implement cause there are some keyboard/hotkeys code and other chat related lifehacks);
- [ ] optional: add private messages (looks like a popup chat window for private messages between users). Xmage has whisper feature, but it hard to use (must send chat message with username to make it private).