Unify hexagon construction data: merge angle + nodeId methods into single flow

[Copilot]

getHexagonAngle and getHexagonRequiredNodeIds were separate methods with independent decomposition schemes (ring-based for angles, shell-based for node IDs) despite always being called together for the same node index. This made the hexagon construction sequence harder to follow and maintain.

Changes

• Unified base table for n ≤ 21: single BaseEntry array with angle + all three node IDs, replacing two separate lookup tables
• Merged decompositions into one method body: ring decomposition (angle) and shell decomposition (node IDs) flow together without separate scoped blocks
• Inlined into generateNextConstructionDataForHexagon: eliminated the intermediate getHexagonConstructionData helper — one method now handles the full hexagon construction sequence
• Removed declarations for getHexagonAngle, getHexagonRequiredNodeIds, and getHexagonConstructionData from the class

// Before: two separate helpers + wrapper
result.angle = getHexagonAngle(n);
getHexagonRequiredNodeIds(n, result.requiredNodeId1, result.requiredNodeId2, result.requiredNodeId3);

// After: single self-contained method
HOST_DEVICE ShapeGeneratorResult ShapeGenerator::generateNextConstructionDataForHexagon()
{
    int n = _nodePos;
    // base table for n <= 21, then ring decomposition (angle) + shell decomposition (nodeIds)
    // ...connection counting...
    ++_nodePos;
    return result;
}