Gravitational Field (HW_GRAVITATION) fixes (#5066)

* Fixes #5065.
* Removes Blue Gemstone cost.
* No longer has a lingering hitbox.
* Deals full damage as one bundle of hits instead of pulsing individual hits.
* Can overlap with itself.
Thanks to @flamefury!

db/re/skill_db.yml

@@ -13247,29 +13247,27 @@ Body:
     MaxLevel: 5
     Type: Magic
     TargetType: Ground
-    DamageFlags:
-      NoDamage: true
     Flags:
       TargetEmperium: true
       IgnoreHovering: true
       TargetHidden: true
     Range: 18
-    Hit: Single
-    HitCount: 1
-    CastCancel: true
-    CastTime: 5000
-    AfterCastActDelay: 1000
-    Duration1:
+    Hit: Multi_Hit
+    HitCount:
       - Level: 1
-        Time: 2000
+        Count: 10
       - Level: 2
-        Time: 2400
+        Count: 12
       - Level: 3
-        Time: 2800
+        Count: 14
       - Level: 4
-        Time: 3200
+        Count: 16
       - Level: 5
-        Time: 3600
+        Count: 18
+    CastCancel: true
+    CastTime: 5000
+    AfterCastActDelay: 1000
+    Duration1: 100
     Cooldown: 5000
     FixedCastTime: 1000
     Requires:
@@ -13284,13 +13282,10 @@ Body:
           Amount: 90
         - Level: 5
           Amount: 100
-      ItemCost:
-        - Item: Blue_Gemstone
-          Amount: 1
     Unit:
       Id: Gravitation
-      Layout: 2
-      Interval: 200
+      Range: 2
+      Interval: 5100 #Using 5s causes a rare bug where another hit occurs at the end
       Target: Enemy
       Flag:
         PathCheck: true