Implement Assistant Manager Chip

[jack89roberts]

Which probably breaks/adds all kinds of things, e.g.:

• Squads can include and score points from managers.
• Transfers can be used on managers.
• Assistant manager chip is active for 3 gameweeks, during which no other chips can be played. Squads only have managers when that chip is active.
• Managers score points based on match outcomes, goals scored/conceded, and league table position vs. opponent
• (at least this season) chip is only available from GW24 onwards
• Budget computation needs to include manager's cost when the assistant manager chip is active
• Players per team limit needs to include manager when the assistant manager chip is active

https://fantasy.premierleague.com/help/new