Add visual aids in analysis board - #19037

Add visual aids for pins, undefended pieces, and checkable kings in analysis board

• Introduces a new boardAnalysis module to detect motifs.

  • Enabled by default. Adds detectPins to identify absolute and significant relative pins.
  • Enabled by default. Adds detectUndefended using Static Exchange Evaluation (SEE) to find hanging or under-defended pieces.
  • Disabled by default. Adds detectCheckable to highlight kings that can be put in check on the next move (including via promotion, castling, or en passant).

• Adds a toggle for each aid.

  

• Aids are disabled if engine eval is not allowed (e.g. correspondence analysis page).

• To avoid unusual legal chess moves, aids are only available in standard, chess960, fromPosition, kingOfTheHill, threeCheck, and racingKings,

• Includes unit tests.

This is how it currently looks.

The same piece can have multiple tags.

The functions return additional information that is not used for the shape creation but that could be useful in the future.

[
  { "pinned": 27, "pinner": 59, "target": 3 }
]
[
  { "square": 22, "materialLoss": 2, "principalAttacker": 50 },
  { "square": 37, "materialLoss": 1, "principalAttacker": 30 }
]
[
  { "king": 0, "check": { "from": 58, "to": 56 } },
  { "king": 55, "check": { "from": 53, "to": 61, "promotion": "knight" } }
]

Example of what could be done with the information provided by the functions: