Implement simultaneous exhibitions play mode and pages #1860
Description
Simuls involve a single player facing several players at once. The concept is taken from real world events. In real life, this involves the simul host moving from table to table to play a single move. When the simul starts, every player starts a game with the host. The simul ends when all games are complete. Simuls are always casual. Rematches, takebacks and adding time are disabled.
From server point of view this feature is rather similar to how tournaments are handled, except this needs only one pairing round where the simul creator is paired with everyone else who joined the event. This means the host have to be enabled to play several games at the same time.
On the client side the host play the games similar to corr games (mini boards below the current game board).
Auto skip to the next game switch button is important!
- Create "Simultaneous exhibitions" list page (https://www.pychess.org/simul) with 3 sections (similar to tournaments page ) with "Newly created simuls", "Playing now" and "Finished" sections. It needs a "HOST A NEW SIMUL" button/link (https://www.pychess.org/simul/new) as well. See https://lichess.org/simul for the layout.
- Implement a new "Host a new simul" page (https://www.pychess.org/simul/new) See https://lichess.org/simul/new for the layout and input fields of the form.
- Implement the simul page before it starts with participants accept/deny users
- If any player (accepted or waiting for approval) has no active simul lobby ws, remove automatically!
- Implement the simul page while it is ongoing like this https://lichess.org/simul/xjIOAD1F
In this example the user DNA-Qdaobio created the simul and plays against everyone else one game per each.
- When all the games are finished the header should change like in this example https://lichess.org/simul/zKHwGeWa
