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/AIObjectiveFixLeak.cs

@@ -24,7 +24,7 @@ namespace Barotrauma
         {
             if (leak.Open == 0.0f) return 0.0f;
 
-            float leakSize = (leak.isHorizontal ? leak.Rect.Height : leak.Rect.Width) * Math.Max(leak.Open, 0.1f);
+            float leakSize = (leak.IsHorizontal ? leak.Rect.Height : leak.Rect.Width) * Math.Max(leak.Open, 0.1f);
 
             float dist = Vector2.DistanceSquared(character.SimPosition, leak.SimPosition);
             dist = Math.Max(dist/100.0f, 1.0f);
@@ -80,7 +80,7 @@ namespace Barotrauma
 
             if (hull == null) return standPos;
             
-            if (leak.isHorizontal)
+            if (leak.IsHorizontal)
             {
                 standPos += Vector2.UnitX * Math.Sign(hull.Position.X - leak.Position.X) * leak.Rect.Width;
             }