Water flow logic tweaking:

- Less fluctuation, water doesn't constantly flow back and forth through gaps.
- Flowing water pushes characters around much more heavily, and the force is applied to the collider in addition to the limbs.
- Vertical gaps don't push characters up/down unless the character is roughly above/below the gap.

+ Renamed some fields in the hull and gap classes (Volume -> WaterVolume, FullVolume -> Volume, public fields start with a capital letter)

Barotrauma/BarotraumaShared/Source/Characters/AI/Objectives/AIObjectiveFixLeaks.cs

@@ -81,7 +81,7 @@ namespace Barotrauma
             if (gap == null) return 0.0f;
 
             //larger gap -> higher priority
-            float gapPriority = (gap.isHorizontal ? gap.Rect.Width : gap.Rect.Height) * gap.Open;
+            float gapPriority = (gap.IsHorizontal ? gap.Rect.Width : gap.Rect.Height) * gap.Open;
 
             //prioritize gaps that are close
             gapPriority /= Math.Max(Vector2.Distance(character.WorldPosition, gap.WorldPosition), 1.0f);