Ball off table

[absynce]

Handle when a ball goes off the table.

Currently, we treat ball-off-table as pocketed.

New scenarios to consider:

1. 8-ball off table on break - 8-ball is spotted. Other player has ball-in-hand behind headstring. (Future: give option to re-rack instead.)
2. 8-ball off table after break - Player loses. 😢
3. Non-8-ball off table on break. Ball not spotted. Other player has ball-in-hand behind headstring. (Future: give option to accept the "table in position".)
4. Non-8-ball off table after break. Ball not spotted. Other player has ball-in-hand. (Future: give option to accept the "table in position".)

TODO:

• Check if ball is off the table instead of considering it pocketed.
• Handle spotting the 8-ball once Spotted balls #34 is merged.

[absynce]

This is the way I decided to handle different variations on PlayersFault.

Alternatively, we could have multiple top-level variants, like this:

      | PlayersFaultSpotEight (Pool AwaitingSpotEightBall)

The downside is that it would become awkward to add a PlayersFaultChooseNextAction.

[absynce]

A new variant here, ChooseNextAction, is the idea I have for allowing multiple actions.

[absynce]

Closing since @w0rm merged it in and handled spotting the 8-ball in #34.