Library/Collision: Implement al::HitInfo and variants

[MonsterDruide1]

On the way to pulling in more collision-specific code, another pretty important class is HitInfo. It stores the result(s) of collisions with some extra meta-data that can be used to appropriately react to the collision at hand.

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This change is 

[tetraxile]

Reviewed 4 of 4 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @MonsterDruide1)

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lib/al/Library/Collision/CollisionPartsTriangle.cpp line 256 at r1 (raw file):

    sead::Vector3f scaled_a1;
    sead::Vector3f scaled_a2;

i wonder if you could move these declarations up a bit to make it more clear what's going on here? (same for DiskHitInfo). maybe something like the following:

Code snippet:

...
tryNormalizeOrZero(&v20);

sead::Vector3f scaled_a1;
sead::Vector3f scaled_a2;
f32 a1_scalar = v20.dot(mTriangle.getFaceNormal() * _70);
f32 a2_scalar = v20.dot(mTriangle.getFaceNormal());
sead::Vector3CalcCommon<f32>::multScalar(scaled_a1, v20, a1_scalar);
sead::Vector3CalcCommon<f32>::multScalar(scaled_a2, v20, a2_scalar);

// or maybe reorder like this if it still matches?

...
f32 a1_scalar = v20.dot(mTriangle.getFaceNormal() * _70);
sead::Vector3CalcCommon<f32>::multScalar(scaled_a1, v20, a1_scalar);

f32 a2_scalar = v20.dot(mTriangle.getFaceNormal());
sead::Vector3CalcCommon<f32>::multScalar(scaled_a2, v20, a2_scalar);