Make sure ActionAnalyzer is aligned with BoardView

[peter1591]

Currently the usage graph is like:

• mcts::ActionAnalyzer uses state::State and FlowControl::ValidActionGetter
• mcts::BoardView uses state::State and FlowControl::ValidActionGetter

Ideally, mcts::ActionAnalyzer should only rely on the information of mcts::BoardView, rather than the full information of state::State

One proposal is to make the usage graph like:

• mcts::BoardView uses state::State and FlowControl::ValidActionGetter
• mcts::ActionAnalyzer uses mcts::BoardView

But, in current implemention, mcts::BoardView needs a 'copy' of the data members of BoardView.

So, it would be better to implement a mcts::BoardRefView, which

1. Construct with a reference to state::State
2. Contains members like RefSelfMinions, RefHandCards, and so on...

Then, the mcts::ActionAnalyzer can uses mcts::BoardRefView to construct action analyzer without unnecessary copy.

The dependency graph will be like:

• mcts::BoardRefView uses FlowControl::ValidActionGetter
• mcts::BoardView uses mcts::BoardRefView
• mcts::ActionAnalyzer uses mcts::BoardRefView

To simplify mcts::BoardRefView, we can just provide some needed online version interfaces for mcts::ActionAnalyzer, and provide traversal bridge interface for mcts::BoardView. In this way, we can eliminate the classes like RefSelfMinions, RefHandCards, etc.

[peter1591]

One proposal:

state::PlayerStateView

• Deck: only report 'count'
• Opponent Hand Card: only report 'hold_from_turn', 'count'
• Opponent Secret: report 'class type'
• Should act like an online filter. Do not store data on members

FlowControl::ValidActionGetter

• Use only state::PlayerStateView

mcts::BoardView

• uses only state::PlayerStateView

mcts::ActionAnalyzer

• uses only state::PlayerStateView

[peter1591]

Fixed.